Secondary autogenic succession in the southern Rocky Mountain Trench

Kemper, John Bryan

doi:10.14288/1.0093297

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Secondary autogenic succession in the southern Rocky Mountain Trench Kemper, John Bryan 1971

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Title	Secondary autogenic succession in the southern Rocky Mountain Trench
Creator	Kemper, John Bryan
Publisher	University of British Columbia
Date Issued	1971
Description	The patterns and rates of forest regeneration on a critical wildlife winter range on the floor of the trench, known locally as Premier Ridge were examined in this study. A nearby western wall of the trench was also investigated to ascertain the effect of elevation on forest regeneration and understory productivity. Forest regeneration in a community which has remained unforested for several as years has pronounced effects on the floristic dynamics and productivity of the understory. On Premier Ridge the greatest floristic change was a rapid increase in pinegrass and a. corresponding decrease in the abundance of all other grass species as the forest regeneration progressed. Forbs varied widely in abundance while shrubs were slower to react to changes in the overstory. Similar trends were observed on Estella Mountain. Productivity of the grass component on the unforested sites was four times that of the forested sites. The production of forbs and some species of shrubs also declined as forest regrowth began. One species, bearberry, increased under light forest canopies. The reduction in productivity and the changes in species composition of-the understory which occur in regenerating forest communities, appear to be detrimental to foraging populations of wild and domestic ungulates. Cattle seem to prefer to graze the open, unforested areas, and as regeneration proceeds, the acreage which they will readily use diminishes. Since there have been few reductions in stock numbers to compensate for this range shrinkage, local overgrazing has become more widespread. The regrowth of the forest reduces the grass, both in terms of quality and quantity. This is the most important component in the diet of cattle and most of the wildlife species using the Premier Ridge area. In addition, bitterbrush, used in the summer by cattle and during the winter by big game species, is quickly eliminated by forest regeneration. Bearberry, which may be used by wildlife to some extent, increases under forest cover. This component does not approach in value or usefulness, the losses that the other components represent to grazing animals. The trees of the south and southwestern aspects are characterized by relatively slow growth rates. Forage production on these slopes is modest; if grazing animals are deemed desirable in the future economy of the East Kootenay, these areas should remain treeless. Growth rates are more favourable on the north and northeast aspects, which are less frequently used as foraging areas by winter wildlife, but may be used as shelter or bedding areas.
Subject	Forest regeneration Forests and forestry -- British Columbia -- Rocky Mountain Trench
Genre	Thesis/Dissertation
Type	Text
Language	eng
Date Available	2011-04-29
Provider	Vancouver : University of British Columbia Library
Rights	For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI	10.14288/1.0093297
URI	http://hdl.handle.net/2429/34141
Degree	Master of Science - MSc
Program	Plant Science
Affiliation	Land and Food Systems, Faculty of
Degree Grantor	University of British Columbia
Campus	UBCV
Scholarly Level	Graduate
Aggregated Source Repository	DSpace

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SECONDARY AUTOGENIC SUCCESSION IN THE SOUTHERN ROCKY MOUNTAIN TRENCH  by  JOHN BRYAN KEMPER B. Sc., U n i v e r s i t y o f B r i t i s h Columbia, 1 9 6 7  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n t h e Department of Plant Science  We a c c e p t t h i s t h e s i s as conforming t o t h e required standard  THE UNIVERSITY OF BRITISH COLUMBIA APRIL, 1971  In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library shall make i t freely ava i lable for reference and  study.  I further agree that permission for extensive copying of this thesis for scholarly, purposes may by his representatives.  be granted by the Head of my  Department or  It is understood that copying or publication  of this thesis for financial gain shall not be allowed without my written  permission.  Department of The University of B r i t i s h Columbia Vancouver 8, Canada  Date  /,  ////  1i  Frontpiece:  P r e m i e r R i d g e , one o f s e v e r a l c r i t i c a l w i n t e r ranges f o r w i l d u n g u l a t e s , which e x i s t on t h e f l o o r o f t h e s o u t h e r n Rocky Mountain Trench. The western edge o f the Rocky Mountains, Hughes Ranges, may he seen on t h e r i g h t o f the p i c t u r e .  Iii ABSTRACT SECONDARY AUTOGENIC SUCCESSION IN THE SOUTHERN ROCKY MOUNTAIN TRENCH The p a t t e r n s and r a t e s o f f o r e s t r e g e n e r a t i o n on a c r i t i c a l w i l d l i f e w i n t e r range on t h e f l o o r o f t h e t r e n c h , known l o c a l l y as Premier Ridge were examined i n t h i s study. gated  A nearby w e s t e r n w a l l o f t h e t r e n c h was a l s o I n v e s t i t o a s c e r t a i n t h e e f f e c t o f e l e v a t i o n on f o r e s t r e -  g e n e r a t i o n and u n d e r s t o r y p r o d u c t i v i t y .  Forest  regeneration  i n a community which has remained u n f o r e s t e d f o r s e v e r a l ' as  y e a r s has pronounced e f f e c t s on t h e f l o r i s t i c p r o d u c t i v i t y of the understory. est  floristic  corresponding  dynamics and  On Premier Ridge t h e g r e a t -  change was a r a p i d i n c r e a s e i n p i n e g r a s s and a. d e c r e a s e i n t h e abundance o f a l l o t h e r  s p e c i e s as t h e f o r e s t r e g e n e r a t i o n p r o g r e s s e d .  grass  Forbs v a r i e d  w i d e l y I n abundance w h i l e shrubs were s l o w e r t o r e a c t t o changes i n t h e o v e r s t o r y .  S i m i l a r t r e n d s were observed  on  E s t e l l a Mountain. P r o d u c t i v i t y o f t h e g r a s s component on t h e unf o r e s t e d s i t e s was f o u r times t h a t o f t h e f o r e s t e d s i t e s . The p r o d u c t i o n o f f o r b s and some s p e c i e s o f shrubs a l s o dec l i n e d as f o r e s t regrowth  began.  One s p e c i e s , b e a r b e r r y ,  i n c r e a s e d under l i g h t f o r e s t c a n o p i e s . The r e d u c t i o n i n p r o d u c t i v i t y and t h e changes i n s p e c i e s c o m p o s i t i o n o f - t h e u n d e r s t o r y which o c c u r i n regenera t i n g f o r e s t communities, appear t o be d e t r i m e n t a l t o f o r a g i n g  iv  populations  o f w i l d and  to p r e f e r to graze generation use  proceeds,  diminishes.  s t o c k numbers overgrazing the  forest  quantity. diet  the  domestic ungulates. open, u n f o r e s t e d  Since  t h e r e h a v e b e e n few  as  readily  reductions  The  component  most o f t h e w i l d l i f e  in  during  q u i c k l y e l i m i n a t e d by  w h i c h may  be  under f o r e s t  the winter  forest  u s e d by  wildlife  cover.  This  to  of.  species using  summer by is  local  by  and  the  In a d d i t i o n , b i t t e r b r u s h , u s e d  and  in  regrowth  Premier Ridge area. cattle  re-  i n terms o f q u a l i t y  I s t h e most i m p o r t a n t  o f c a t t l e and  and  range shrinkage,  become more w i d e s p r e a d .  r e d u c e s 'the g r a s s , b o t h This  areas,  the acreage which they w i l l  t o compensate f o r t h i s  has  C a t t l e seem  the  in  the  b i g game s p e c i e s ,  regeneration.  Bearberry,  some e x t e n t ,  component does n o t  increases approach i n -a  value  or usefulness,  represent  to g r a z i n g The  are  the  on  t r e e s of the  these  south  relatively slopes  areas  a r e more f a v o u r a b l e are  less  but  may  on  should  u s e d as  and  southwestern  aspects  slow growth r a t e s .  f u t u r e economy o f t h e remain t r e e l e s s .  the n o r t h  f r e q u e n t l y used as be  components  i s modest; i f g r a z i n g  a r e deemed d e s i r a b l e i n t h e Kootenay, these  other  animals.  c h a r a c t e r i z e d by  production  l o s s e s that the  and  northeast  f o r a g i n g areas  s h e l t e r or bedding  by  areas.  Forage  animals East  Growth  • rates  aspects, winter  which  wildlife,  V  TABLE OP  CONTENTS Page  I  INTRODUCTION A. B. C.  II  Area Description Climate . The P r o b l e m  METHODS AND  A. B. C. D.  Criteria for Site Selection S i t e D e s c r i p t i o n Techniques Determination of Characteristic S t a n d Age Annual P r o d u c t i v i t y Assessments  4. OBSERVATIONS AND A.  Timber.... B i t t e r b r u s h and S o a p o l a l l i e . G r a s s e s , F o r b s and D w a r f Shrubs Bearberry  2. 3. 4. 5.  Skookumchuck P r a i r i e The N a t u r a l G r a s s l a n d . . . Premier Ridge Non-forested Sites Premier Ridge Forested Sites E s t e l l a Mountain Forested Sites E s t e l l a Mountain -  Floristic  2.  15 17 17 18 20 20  22  Non-forested Sites  1.  11 13  RESULTS  Site Descriptions 1.  B.  2 8 9  MATERIALS  1. 2. 3.  III  and H i s t o r y  23 25 3 1 42  49 5^  Dynamics  Premier Ridge S i t e s  5^  a. b.  Grasses Forbs  56 57  c.  Shrubs  60  E s t e l l a Mountain a. b. c.  Grasses Forbs Shrubs  Sites  60 6C 67 P7 1  vi C.  Page  1.  E. F. G.  P r e m i e r Ridge... E s t e l l a Mountain,  ' 73 75 75 77 .  80 80 80 83 83 85 85 85 85  85 87  S i t e H i s t o r y and Paths o f S u c c e s s i o n on P r e m i e r Ridge ..  92  S i t e H i s t o r y and Paths o f S u c c e s s i o n on E s t e l l a . Mountain  95  P r o d u c t i v i t y o f the Forest, 1. 2.  H.  Porb P r o d u c t i v i t y . . . . . . . Dwarf Shrub Productivity d. B e a r b e r r y Productivity e. Bitterbrush Productivity f. So&polallie Productivity... E s t e l l a Mountain a. Grass P r o d u c t i v i t y b. Forb P r o d u c t i v i t y c. Dwarf Shrub Productivity d. B e a r b e r r y Productivity e. Bitterbrush Productivity f. Soapolallie Productivity  O v e r s t o r y Community C o m p o s i t i o n . . . . 1. 2.  71  Grass P r o d u c t i v i t y  t>. c.  2.  7±  P r e m i e r Ridge a.  D.  71  Productivity  P r e m i e r Ridge , E s t e l l a Mountain...,  Aggregate U n d e r s t o r y P r o d u c t i v i t y . . 1. 2.  Premier Ridge... E s t e l l a Mountain  104 '10k  106 108  108 113  vii LIST  OP  TABLES  Page I  The I n f l u e n c e o f c h a r a c t e r i s t i c s t a n d age on the s p e c i e s dynamics o f t h e u n d e r s t o r y g r a s s species  59  The i n f l u e n c e o f f o r e s t canopy on t h e p e r c e n t ground c o v e r o f t h e g r a s s component o f t h e understory  59  The abundance o f shrubs on the P r e m i e r Ridge s i t e s , i n r e l a t i o n to c h a r a c t e r i s t i c stand age and f o r e s t canopy  66  The abundance o f s e v e r a l s p e c i e s o f g r a s s e s as measured by p e r c e n t ground c o v e r on E s t e l l a Mountain  69  V  The abundance o f f o r b s as measured b y p e r c e n t ground c o v e r on E s t e l l a Mountain  70  VI  S t a t i s t i c s f o r shrub abundance on E s t e l l a Mountain  VII  S i t e s t: a t i s t i c s f o r t r e e s , P r e m i e r R i d g e ,  VIII  Site s t a t i s t i c s for trees, Estella  IX  S t a t i s t i c s f o r stumps, P r e m i e r R i d g e , 1969  9'6  X  F o r e s t c o v e r o f P r e m i e r Ridge s i t e s , p a s t and present  97  XI  The paths o f s u c c e s s i o n on P r e m i e r Ridge  98  XII  S t a t i s t i c s f o r stumps, E s t e l l a Mountain, 1969.  99  XIII  F o r e s t c o v e r o f E s t e l l a Mountain, p a s t and  II  III  IV  1969..  1969  ,  Mountain,  present XIV  The paths o f s u c c e s s i o n on E s t e l l a Mountain  XV  S t a t i s t i c s r e l a t i n g t o wood p r o d u c t i o n , P r e m i e r Ridge s i t e s . . . .  71  91 93  • 100  102-103 •••105  viii XVI XVII XVIII  Page  Statistics relating to wood production, Estella Mountain sites  107  The aggregate annual understory productivity on Premier Ridge.  112  The aggregate annual understory productivity on Estella Mountain  116  ix  LIST OP FIGURES Page 1.  Map  o f t h e Premier Ridge s t u d y a r e a  3  2.  Map  o f t h e E s t e l l a Mountain s t u d y a r e a  4  3.  I l l u s t r a t i o n of the d e t e r m i n a t i o n of c h a r a c t e r i s t i c s t a n d age  l6  4.  The Skookumchuck P r a i r i e , a n a t u r a l g r a s s l a n d .  24  5.  The b l u e g r a s s - n e e d l e g r a s s p l o t , l o c a t e d A l k a l i Lake  near 26  ;  6.  The b l u e g r a s s - n e e d l e g r a s s e x c l o s u r e  27  7.  The b i t t e r b r u s h s i t e  29  8.  A close-up of the b i t t e r b r u s h e x c l o s u r e  30  9.  The r e l i c t wheatgrass s i t e  32  10.  R e g e n e r a t i o n on t h e s t e e p w e s t e r n a s p e c t s  has  been slow  34  11.  The  34  12.  The young Douglas f i r . s i t e  35  13.  The middle-aged  37  14.  The mature Douglas f i r s i t e  38  15.  The young ponderosa p i n e s i t e . .  4-.1  16.  The middle-aged  44  17.  A c l o s e - u p o f the middle-aged  " t e r r a c e " a r e a o f Premier. Ridge  Douglas f i r s i t e  ponderosa p i n e s i t e ponderosa p i n e  site  44  18.  The c l i m a x ponderosa p i n e s t a n d  45  19.  The l o d g e p o l e p i n e s t a n d on Premier Ridge  46  20.  The r e g e n e r a t i n g Douglas f i r s t a n d on E s t e l l a Mountain  48  ,  X  Page 21.  The  l a r c h stand  22.  The  l o d g e p o l e p i n e s t a n d on E s t e l l a  50  Mountain  51  23.  The s e r a i f e s c u e s i t e  53  24. 25.  The s e r a i wheatgrass s i t e The abundance o f s e v e r a l s p e c i e s o f g r a s s e s on P r e m i e r Ridge as I n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  55 58  The abundance o f s e v e r a l s p e c i e s o f f o r b s on Premier Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age  6l  The abundance o f s e v e r a l s p e c i e s o f f o r b s on Premier Ridge as i n f l u e n c e d by f o r e s t canopy.  62  The abundance o f t i m b e r m i l k v e t c h and BaIsammo r h i z a s a . g i t t a t a on Premier Ridge as i n f l u e n c e d by f o r e s t canopy  63  The abundance o f f o r b s on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy  64  The abundance o f dwarf shrubs on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy  65  The abundance o f s e v e r a l s p e c i e s o f g r a s s e s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy  68  26.  27.  28.  29.  30.  31.  32.  33.  The abundance o f f o r b s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy '  • 72  The p r o d u c t i v i t y o f g r a s s on Premier Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c stand age and f o r e s t canopy  74  The p r o d u c t i v i t y o f g r a s s on Premier R i d g e as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The a n n u a l p r o d u c t i v i t y o f dwarf shrubs on Premier Ridge as I n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy... The a n n u a l p r o d u c t i v i t y o f b e a r b e r r y on Premier Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The a n n u a l p r o d u c t i v i t y o f b i t t e r b r u s h ( t w i g s a n d j t h e i r l e a v e s o n l y ) on Premier R i d g e as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The a n n u a l p r o d u c t i v i t y o f s o a p o l a l l i e ( t w i g s and l e a v e s ) as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The p r o d u c t i v i t y o f g r a s s e s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy. The p r o d u c t i v i t y o f f o r b s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The p r o d u c t i v i t y o f dwarf shrubs on E s t e l l a Mountain a.s i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy The a n n u a l p r o d u c t i v i t y o f b e a r b e r r y on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy  :  The a n n u a l p r o d u c t i v i t y o f s o a p o l a l l i e ( t w i g s and l e a v e s ) as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy, E s t e l l a s i t e s . . .  I n e aggregate a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f Premier Ridge as i n f l u e n c e d by f o r e s t canopy.  xii Page 45.  46.  47.  The aggregate a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age.........  I l l  The aggregate a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age  11.4  The aggregate a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a Mountain as i n f l u e n c e d by f o r e s t canopy  115  xiv  (A.e.- -*.v\v)  ACKNOWLEDGEMENTS I would l i k e t o thank Dr. V. C. B r i n k f o r h i s c o n t i n u i n g encouragement and t h o u g h t f u l g u i d a n c e .  Dr. B r i n k ,  Dr. P. J . Bandy and Dr. I . McTaggart Cowan v i s i t e d t h e study a r e a and made many h e l p f u l s u g g e s t i o n s .  Valuable  criticism  was p r o v i d e d by o t h e r members o f my committee, i n c l u d i n g Dr. W. D. K i t t s and Dr. L. M. L a v k u l i c h .  Ray Demarchi and  s t a f f o f t h e Cranbrook o f f i c e o f t h e P i s h and W i l d l i f e Branch a s s i s t e d t h i s p r o j e c t i n many ways; w i t h t h e i r and  cooperation  t h a t o f t h e B. C. F o r e s t S e r v i c e , t h e p r o j e c t went  smoothly. The  F i s h and W i l d l i f e Branch supported  work i n t h e summers o f 1968  and 1969  and t h e i r  the f i e l d financial  a s s i s t a n c e was g r e a t l y a p p r e c i a t e d . Mr. summer o f 1969  R i c k Howie s e r v e d as f i e l d a s s i s t a n t i n t h e and h i s h e l p was much a p p r e c i a t e d .  The measure o f c o o p e r a t i o n which was a c h i e v e d  with  the B.' C. F o r e s t S e r v i c e , t h e B. C. F i s h and W i l d l i f e Branch and  the l o c a l ranchers  and c i t i z e n s was most g r a t i f y i n g .  1  INTRODUCTION Recent changes i n t h e p o p u l a t i o n s o f d e e r , e l k and b i g h o r n sheep i n t h e E a s t Kootenay r e g i o n have been l i n k e d to changes i n t h e v e g e t a t i o n o f t h e c r i t i c a l w i n t e r ranges, brought about by l o g g i n g , b u r n i n g and g r a z i n g by domestic animals. Widespread l o g g i n g and b u r n i n g o f t h e montane f o r e s t s on t h e f l o o r o f t h e s o u t h e r n Rocky Mountain  Trench  a t t h e t u r n o f t h e c e n t u r y removed almost a l l t h e mature f o r e s t s a t low e l e v a t i o n s .  The removal o f t h e f o r e s t  o v e r s t o r y I n i t i a t e d t h e development o f s e r a i communities dominated by g r a s s e s , f o r b s and s h r u b s ; t h e r e s u l t was an increase i n forage f o r ungulates.  Small l o c a l populations  o f t h e l a r g e u n g u l a t e s , e l k , b i g h o r n sheep, mule deer and w h i t e - t a i l e d d e e r , p r e v i o u s l y c o n s i d e r e d n o t t o be abundant, responded t o t h i s expanding d i s t r i b u t i o n and numbers.  food s u p p l y by i n c r e a s i n g E a r l y s e t t l e r s i n the area  advantage o f t h i s young s e r a i v e g e t a t i o n t o r a i s e  their took  livestock.  S i n c e 1 9 3 0 f o r e s t f i r e s have been uncommon i n t h e s o u t h e r n Rocky Mountain Trench, and f o r e s t r e g e n e r a t i o n on the logged and burned a r e a s has been r a p i d . r a t e s o f domestic  Heavy s t o c k i n g  c a t t l e on those a c r e s c o n s i d e r e d as c r i t i -  c a l w i n t e r ranges f o r w i l d u n g u l a t e s i s t a x i n g t h e e x i s t i n g range r e s o u r c e .  A r e c e n t d i e - o f f i n Rocky Mountain b i g h o r n  2 sheep has f o c u s e d a t t e n t i o n on t h e problem,  r e s u l t i n g i n the  i n i t i a t i o n o f range and a n i m a l - o r i e n t e d r e s e a r c h t o examine the problem and suggest ways o f p r e v e n t i n g i t s r e c u r r e n c e . T h i s s t u d y was 1.  determine:  The p a t h and r a t e s o f s u c c e s s i o n o f t h e  vegetat ion. 2.  i n i t i a t e d to  -^'g?  >«;^^  The e f f e c t o f t r e e r e g e n e r a t i o n on the  floristic  c o m p o s i t i o n o f the u n d e r s t o r y . 3.  The e f f e c t o f f o r e s t r e g e n e r a t i o n on the a n n u a l  understory p r o d u c t i v i t y . 4.  The  i n f l u e n c e of t h e c u r r e n t g r a z i n g p r a c t i c e s  on t h e open s e r a i r a n g e l a n d s . The w i n t e r range s e l e c t e d f o r i n t e n s i v e study Premier Ridge and a d j a c e n t E s t e l l a Mountain.  was  A s e r i e s of  e x c l o s u r e p l o t s were e s t a b l i s h e d under the v a r i o u s types of secondary and c l i m a x f o r e s t s which e x i s t i n the a r e a . Three p l o t s were e s t a b l i s h e d on open communities which have f a i l e d t o r e g e n e r a t e t o f o r e s t a f t e r l o g g i n g which about 1910.  occurred  One p l o t on a n a t u r a l g r a s s l a n d , l o c a t e d near  the s t u d y area,.was i n c l u d e d i n t h e s t u d y f o r  comparative  purposes. A.  Area D e s c r i p t i o n and H i s t o r y The s o u t h e r n Rocky Mountain Trench  i n t h e east  Kootenay r e g i o n l i e s i n the s o u t h e a s t c o r n e r o f B r i t i s h Columbia, bounded by the A l b e r t a b o r d e r on the e a s t , the  Key t o t h e s i t e s on P r e m i e r R i d g e . 1  Mature Douglas f i r  2  Young Douglas f i r  3  Bitterbrush  4  Poa - S t i p a u n f o r e s t e d  5  M i d d l e - a g e d ponderosa p i n e  6  Bluebunch wheatgrass u n f o r e s t e d  7  Young ponderosa p i n e  8  M i d d l e - a g e d Douglas f i r  9  C l i m a x ponderosa p i n e  (Purshia) unforested  Key t o the  sites  1  R e g e n e r a t i n g Douglas f i r  2  Larch  3  Serai  4  Lodgepole P i n e  fescue  5 ' S e r a i bluebunch  wheatgrass  4  Estella  Mountain  SCALE 150,000 e  '~  Montana b o r d e r on the s o u t h and t h e P u r e e l l Mountains the west.  on  The n o r t h e r n boundary o f the " s o u t h e r n t r e n c h "  i s l o c a t e d i n the v i c i n i t y o f C a n a l F l a t s , B r i t i s h  Columbia.  S o i l s u r v e y s and g e o l o g i c a l d a t a f o r t h e a r e a have been r e c o r d e d by K e l l e y and Sprout  ( 1 9 5 6 ) and G. G. Runka  (1970).  The h i s t o r y o f t h e E a s t Kootenay r e g i o n c e n t r e s a.bout the e x p l o i t a t i o n o f i t s n a t u r a l r e s o u r c e s , f u r s , m i n e r a l s and a r a b l e l a n d s .  B e f o r e the advent  of white  man,  I n d i a n s g r a z e d h o r s e s on the s c a n t y n a t u r a l g r a s s l a n d s which e x i s t e d on the t r e n c h f l o o r ,  ( K e l l e y and Sprout 1 9 5 6 ) .  Early  e x p l o r e r s i n 1807 n o t e d t h a t the K o o t e n a i I n d i a n s were "a s c r u f f y l o t " but t h a t t h e y p o s s e s s e d horses.  exceptionally  fine  These e x p l o r e r s a l s o n o t e d the absence o f b i g  game i n t h e a r e a , s t a t i n g t h a t food was  difficult  to o b t a i n .  Another f a c t which f u r t h e r r e v e a l s the s c a r c i t y o f l a r g e u n g u l a t e s i s t h a t the K o o t e n a i I n d i a n s were o b l i g e d t o make two a n n u a l f o r a y s t h r o u g h t h e Crowsnest Pass i n t o the p l a i n s to hunt b i s o n .  These a n i m a l s were p r o b a b l y t h e i r o n l y s t a b l e  meat s o u r c e f o r much o f the y e a r . In the e a r l y l 8 0 0 ' s the f u r t r a d e was about 50 y e a r s , g i v i n g way  active for  t o a g o l d r u s h on t h e W i l d h o r s e  R i v e r ( t h e n c a l l e d the Stud Horse R i v e r ) i n 1 8 6 3 .  The demand  f o r meat i n the m i n i n g camps p r o b a b l y e x e r t e d moderate p r e s s u r  6  on t h e r e l a t i v e l y s m a l l p o p u l a t i o n s o f w i l d u n g u l a t e s which existed i n the area a t that time.  C a t t l e were few i n t h e  a r e a u n t i l 1890 a t which time s e v e r a l r a n c h e r s had developed herds o f 200 t o 300 head ( K e l l e y and Sprout  1956).  E a r l y l o g g i n g r e c o r d s have proven d i f f i c u l t t o obtain f o r t h i s area.  A p p a r e n t l y t h e e a r l i e s t m i l l s opened  about. 1 8 8 4 , and by 1910 r a i l w a y l o g g i n g was b e i n g p r a c t i c e d on t h e t r e n c h f l o o r .  S l a s h f i r e s and a c c i d e n t a l f i r e s were  common f o l l o w i n g l o g g i n g .  V i r t u a l l y a l l o f t h e bottom l a n d s  o f t h e t r e n c h f l o o r were f i r e d one o r more t i m e s . The o r i g i n a l f o r e s t c o v e r o f t h e t r e n c h f l o o r was predominately  a mature Montane F o r e s t o f ponderosa p i n e  (Pinus ponderosa) and Douglas f i r (Pseudotsuga m e n z i e s i i v a r . g l a u c a ) o c c u r r i n g i n mixed stands w i t h o c c a s i o n a l pure stands o f e i t h e r s p e c i e s .  B l a c k cottonwood  t r i c h o c a r p a ) a.nd Englemann spruce  (Populus  ( P i c e a engelmanni) were  common i n m o i s t draws and a l o n g r i v e r  channels.  On t h e e a s t e r n w a l l o f t h e t r e n c h , Douglas f i r p r e s e n t l y predominates;  ponderosa p i n e i s more abundant.  on t h e d r i e r east w a l l and t r e n c h f l o o r , o c c u r r i n g t o a . • maximum e l e v a t i o n o f 4 , 0 0 0 f t . Above t h i s  elevation,  Englemann spruce d i s p l a c e s Douglas f i r on t h e more m o i s t n o r t h and n o r t h e a s t a s p e c t s .  Western l a r c h ( L a r i x o c c i -  d e n t a l ! s ) i s a r u d e r a l and i s common i n m o i s t  locations.  At a l l e l e v a t i o n s , n o r t h and n o r t h e a s t s l o p e s a r e more  7  h e a v i l y t i m b e r e d than t h e i r s o u t h and southwest parts.  Lodgepole p i n e ( P i n u s c o n t o r t a v a r .  counter-  latifolia)  occurs s p o r a d i c a l l y , at a l l e l e v a t i o n s , u s u a l l y f o l l o w i n g fire. N a t u r a l g r a s s l a n d s a r e r e s t r i c t e d t o d r y benches of  the t r e n c h f l o o r where Bluebunch wheatgrass  (Agropyron  s p i c a t u m ) and rough f e s c u e ( F e s t u c a s c a b r e l l a ) were once the dominant s p e c i e s .  However, heavy g r a z i n g p r e s s u r e by  domestic s t o c k reduced or e l i m i n a t e d t h e bunchgrasses  re-  p l a c i n g them w i t h s p a r c e stands o f p e r e n n i a l Poa and  Stipa,  and a n n u a l g r a s s e s and weeds which p r e s e n t l y c o n s t i t u t e the main c o v e r . E r r a t i c l o g g i n g and b u r n i n g on the t r e n c h f l o o r has l e f t a complex v e g e t a t i o n a l p a t t e r n o f secondary w i t h o c c a s i o n a l open s e r a i and n a t u r a l g r a s s l a n d s .  forests On  l i m i t e d a c r e a g e s , u s u a l l y on s o u t h o r soxathwest s l o p e s , p r e v i o u s l y logged a r e a s have not y e t r e g e n e r a t e d t o f o r e s t cover.  A c o m b i n a t i o n of e n v i r o n m e n t a l f a c t o r s c o u p l e d w i t h  heavy g r a z i n g p r e s s u r e by b o t h w i l d and domestic may  be r e t a r d i n g f o r e s t r e g e n e r a t i o n .  ungulates  Many o f these open  areas a r e regarded as c r i t i c a l w i n t e r ranges f o r w i l d ungulates. An a c t i v e C h r i s t m a s t r e e i n d u s t r y i s p r a c t i c e d i n s e v e r a l a r e a s ; t h e t r e e s a r e cut so they w i l l  regrow.  V i r t u a l l y a l l o f the open and semi-open r a n g e l a n d  8 o f the t r e n c h f l o o r i s g r a z e d by c a t t l e and many o f these areas support some w i n t e r i n g n a t i v e u n g u l a t e s from December to May.  In ea.rly s p r i n g , a r a b l e l a n d s a r e a l s o used by  n a t i v e game a n i m a l s . B.  Climate The c l i m a t e o f the s o u t h e r n Rocky Mountain Trench  i s sub-humid w i t h an a n n u a l p r e c i p i t a t i o n o f 14 - 20 i n c h e s per y e a r .  Much o f t h i s f a l l s as snow d u r i n g the w i n t e r  months from November t o F e b r u a r y , a l t h o u g h a secondary i n p r e c i p i t a t i o n o c c u r s i n June.  The  peak  s p r i n g thaw u s u a l l y  p r o v i d e s adequate s o i l m o i s t u r e f o r growth, b e i n g r e i n f o r c e d by the June r a i n s ( K e l l e y and Sprout  1956).  The d i f f e r e n c e  between good and poor growing y e a r s i s r e l a t e d t o the June precipitation.  D u r i n g the summer o f 1 9 6 9 , when most o f  the p r o d u c t i v i t y samples were t a k e n , the June p r e c i p i t a t i o n was  remarkably  h i g h (about 7 " ) .  Hence t h e v a l u e s f o r p r o -  d u c t i o n s h o u l d be c o n s i d e r e d as maximal r a t h e r than  average.  Summer c o n v e c t i v e and o r o g r a p h i c p r e c i p i t a t i o n extend the growing temperatures  season on t h e t r e n c h f l o o r .  100°  High summer  on the t r e n c h f l o o r , p a r t i c u l a r l y on south  southwest s l o p e s where ambient a i r temperatures  f l o o r above  4,000  The  and  exceeding  F a r e sometimes r e c o r d e d , s e v e r e l y l i m i t the  ness o f summer p r e c i p i t a t i o n .  may  effective-  east w a l l o f t h e t r e n c h  f t . i s c o o l e r and r e c e i v e s more f r e q u e n t  9  r a i n f a l l throughout t h e y e a r from p r e v a i l i n g w e s t e r l y weather  systems. K e l l e y and Sprout ( 1 9 5 6 ) r e p o r t e d t h a t t h e  growing season on the t r e n c h f l o o r was a p p r o x i m a t e l y 180 days, from A p r i l 15 t o e a r l y October.  At h i g h e r e l e v a t i o n s  the growing season i s c o r r e s p o n d i n g l y s h o r t e r , but c o o l e r summer t e m p e r a t u r e s p e r m i t almost c o n t i n u o u s growth.  On  the  t r e n c h f l o o r dormancy i n g r a s s e s and f o r b s o c c u r s about  the  second week i n J u l y .  C.  The  Problem F o l l o w i n g e x t e n s i v e l o g g i n g and b u r n i n g on t h e  t r e n c h f l o o r e a r l y i n t h e t w e n t i e t h c e n t u r y , b i g game p o p u l a t i o n s i n c r e a s e d , r e s p o n d i n g t o the i n c r e a s e d fora,ge made a v a i l a b l e by man's a l t e r a t i o n o f t h e h a b i t a t .  A  second s e r i e s o f f i r e s e a r l y i n t h e t h i r d decade d e s t r o y e d many o f the young f o r e s t s w h i c h had begun t o r e - e s t a b l i s h on t h e t r e n c h f l o o r .  Ranchers took advantage o f t h i s  new  range r e s o u r c e by i n c r e a s i n g t h e s t o c k i n g r a t e s o f domestic c a t t l e and h o r s e s . The numbers o f l a r g e w i l d u n g u l a t e s remains h i g h e r than t h o s e r e c o r d e d p r e v i o u s l y , however a g r a d u a l d e c l i n e has been noted s i n c e 19^5*  as t r e e s once a g a i n b e g i n t o be  predominant o v e r the t r e n c h f l o o r .  The i n s t i t u t i o n o f v e r y  e f f e c t i v e f i r e p r o t e c t i o n f o r the young f o r e s t s has r e s u l t e d i n a c o n t i n u a l s h r i n k i n g o f open range a c r e a g e .  Stocking  10 r a t e s i n most s e c t i o n s o f t h e t r e n c h have n o t been a d j u s t e d to a l l o w f o r t h i s d e c r e a s e I n range acreage;  consequently,  fewer and fewer a c r e s a r e f o r c e d t o support  t h e same numbers  of stock. passing  Thus, o v e r g r a z i n g may be more severe w i t h each  year. S m a l l h i l l s o r anomalies on t h e t r e n c h f l o o r have  been used as t r a d i t i o n a l w i n t e r ranges by l o c a l p o p u l a t i o n s o f mule d e e r , w h i t e - t a i l e d d e e r , Rocky Mountain b i g h o r n and  elk.  animals  With the exception o f w h i t e - t a i l e d deer,  sheep  these  summer a t h i g h e l e v a t i o n s i n t h e Rocky M o u n t a i n s ,  u s i n g v a s t areas which i n t h e f o r e s e e a b l e f u t u r e w i l l n o t be g r e a t l y m o d i f i e d by man.  The c o n t i n u e d s u r v i v a l o f t h e s e  p o p u l a t i o n s i s dependent upon c r i t i c a l w i n t e r and e a r l y s p r i n g ranges which d o t t h e t r e n c h f l o o r .  The u t i l i z a t i o n o f t h e s e  ranges c r i t i c a l f o r w i l d l i f e i n w i n t e r , by c a t t l e d u r i n g t h e summer reduces t h e f o r a g e a v a i l a b l e f o r w i l d l i f e .  s  In o r d e r t o o b t a i n some measure o f t h e e f f e c t s o f f o r e s t r e g e n e r a t i o n and s u c c e s s i o n on t h e s p e c i e s  composition  and p r o d u c t i v i t y o f t h e u n d e r s t o r y community, t h i s study was e s t a b l i s h e d under the j o i n t c o o p e r a t i o n o f t h e U n i v e r s i t y o f B r i t i s h Columbia and t h e B r i t i s h Columbia P i s h and W i l d l i f e Branch.  11  II A.  METHODS AND MATERIALS  Criteria for Site  Selection  A r e c o n n a i s s a n c e s u r v e y o f t h e Premier Ridge  area  and t h e s u r r o u n d i n g t r e n c h f l o o r r e v e a l e d t h a t g r a z i n g was c o n c e n t r a t e d p r i m a r i l y on s o u t h and southwestern  s l o p e s and  the a d j a c e n t f l a t open a r e a s o f t h e t r e n c h f l o o r .  The  v e g e t a t i o n o f the r i d g e appears t o be s i m i l a r t o t h e communities common t o t h e f l o o r o f t h e t r e n c h . t a t i o n o f t h e a d j a c e n t east w a l l o f t h e t r e n c h  The vege(Estella  Mountain) i s d i s t i n c t l y d i f f e r e n t , r e f l e c t i n g i n c r e a s e d p r e c i p i t a t i o n and c o o l e r temperatures higher elevations.  associated with  Aspect has a profound  e f f e c t on m i c r o -  c l i m a t e i n t h i s a r e a , p a r t i c u l a r l y on e f f e c t i v e s o i l m o i s t u r e ; c o n s e q u e n t l y , t h e s i t e s s e l e c t e d f o r s t u d y were r e s t r i c t e d to  south and southwestern  aspects.  The f o r e s t c o v e r o f Premier Ridge i s composed o f ponderosa p i n e and Douglas f i r ; l o d g e p o l e p i n e and l e s s commonly l a r c h , u s u a l l y f o l l o w f i r e . ponderosa p i n e i s absent b u t western  On n o r t h e a s t s l o p e s , l a r c h i s common i n  moist draws. The mature montane f o r e s t stands o f a few decades ago were l a r g e l y c l e a r c u t , l e a v i n g a . s e r i e s o f secondary stands o f v a r y i n g ages and s p e c i e s c o m p o s i t i o n .  Douglas  f i r and ponderosa p i n e were t h e most abundant and widespread s p e c i e s , c o n s e q u e n t l y young, mature, and c l i m a x  12  stands o f t h e s e s p e c i e s were sought f o r i n t e n s i v e studyon Premier Ridge.  One l o d g e p o l e s t a n d on Premier was a l s o  s e l e c t e d and t h r e e open s e r a i range s i t e s were i n c l u d e d , r e p r e s e n t i n g a r e a s which were once timbered and l o g g e d , but which f a i l e d t o r e g e n e r a t e t o t r e e s .  One s i t e  esta-  b l i s h e d by t h e B r i t i s h Columbia F o r e s t S e r v i c e , G r a z i n g D i v i s i o n , on t h e Skookumchuck P r a i r i e , a n a t u r a l g r a s s l a n d , was i n c l u d e d i n t h i s s t u d y f o r c o m p a r a t i v e F i v e s i t e s were s e l e c t e d on nearby Mountain  purposes.  Estella  t o measure t h e e f f e c t o f i n c r e a s e d e l e v a t i o n and  p r e c i p i t a t i o n on s u c c e s s i o n and p r o d u c t i v i t y .  Two o f t h e s e  s i t e s were logged i n t h e 1 9 5 0 ' s ; one i s a l a r c h s t a n d and the o t h e r a Douglas f i r s i t e .  The r e m a i n i n g t h r e e s i t e s  on E s t e l l a a r e s i t u a t e d on a 1 9 3 ^ burn w h i c h swept t h e mountain from bottom t o t o p .  A l o d g e p o l e s i t e was e s t a - .  b l i s h e d on an a r e a which has been dominated pine s i n c e the f i r e .  by l o d g e p o l e  An open f e s c u e and an open  r  bunchgrass  s i t e were e s t a b l i s h e d on two a r e a s which have remained unforested since the f i r e . At each s i t e a 3 0 ' x 3 0 ' e x c l o s u r e , e i g h t f e e t h i g h was c o n s t r u c t e d , e x c l u d i n g a l l u n g u l a t e s from t h e plot.  W i t h i n t h i s a r e a e i g h t e e n meter square quadrats were  l a y e d out i n a fixed, p a t t e r n , from which t h e p r o d u c t i v i t y c l i p s were taken.. A 100 f o o t square m a c r o p l o t , c o n c e n t r i c w i t h t h e e x c l o s u r e , was l a i d out a t each s i t e .  (This area  13  was n o t f e n c e d i n any way.)  Trees and l a r g e shrubs were  sampled from the m a c r o p l o t ; g r a s s e s , f o r b s and dwarf were sampled  from the e x c l o s u r e .  was completed by August May  1969.  1968.  shrubs  Construction of a l l exclosures  Two  s i t e s were added i n e a r l y  These were an open b l u e g r a s s - n e e d l e g r a s s s i t e  and an open b i t t e r b r u s h s i t e , b o t h l o c a t e d on P r e m i e r R i d g e . In two c a s e s , the open bluebunch wheatgrass s i t e  :  on P r e m i e r Ridge and t h e open f e s c u e s i t e on E s t e l l a , the e n t i r e m a c r o p l o t was  fenced.  B.  Techniques  Site Description  The a s p e c t and p e r c e n t s l o p e o f each p l o t was • r e c o r d e d i n t h e f o l l o w i n g manner.  The p e r c e n t s l o p e was  o b t a i n e d w i t h a Suunto L e v e l by s i g h t i n g from t h e c e n t r e o f t h e upper m a c r o p l o t boundary m a c r o p l o t boundary. slope d i r e c t l y . )  t o the c e n t r e o f t h e lower  (The i n s t r u m e n t s c a l e reads p e r c e n t  The a s p e c t was measured by compass, con-  s i d e r i n g the m a c r o p l o t as a p l a n e s u r f a c e ; the d i r e c t i o n , i n degrees from magnetic n o r t h , i n w h i c h the p l a n e was t i l t e d was c o n s i d e r e d t o be the a s p e c t .  A map  was drawn f o r each m a c r o p l o t showing  the  l o c a t i o n o f each t r e e , stump and l a r g e s h r u b , i n c l u d i n g a r e f e r e n c e number under which the v a r i o u s parameters c r i b i n g t h a t p l a n t were l i s t e d .  A canopy map  des-  of t h e f o r e s t  o v e r s t o r y was made f o r the m a c r o p l o t u s i n g a 3 meter square  14  g r i d of 100 p o i n t s .  At each p o i n t on t h e g r i d a. v e r t i c a l  s i g h t i n g was taken w i t h a G i m b a l l s i g h t (Dodd l i v i n g branches, "hits".  1969).  Only-  t r u n k s and l i m b s were r e c o r d e d as canopy  Open sky o r dead branches were r e c o r d e d as m i s s e s .  For each s i g h t i n g t h e h i t o r miss was r e c o r d e d f o r a. s m a l l dot on t h e m i r r o r o f t h e i n s t r u m e n t .  S i n c e t h e g r i d has  100 p o i n t s , t h e number o f h i t s r e c o r d e d i s t h e p e r c e n t f o r e s t canopy c o v e r , a t eye l e v e l ( 5 ) - T h i s method s h o u l d 1  not be confused w i t h a s i m i l a r method which r e c o r d s t h e canopy cover o f each t r e e on an i n d i v i d u a l b a s i s .  Since  canopies o v e r l a p , v a l u e s above 1 0 0 $ a r e common, but t h i s study c o n s i d e r e d t h e canopy as a u n i t , and u s i n g t h i s system, v a l u e s h i g h e r than 80$> a r e uncommon. Each t r e e mapped i n t h e m a c r o p l o t  was c l a s s i f i e d  by s p e c i e s , age, d i a m e t e r b r e a s t h e i g h t (DBH), d i a m e t e r a t stump h e i g h t (DIH) and t o t a l h e i g h t . The  l o c a t i o n , age a t c u t t i n g t i m e , s p e c i e s and  c o n d i t i o n o f a l l stumps i n t h e macroplot  was r e c o r d e d .  S o a p o l a l l i e ( S h e r p h e r d i a canadensis ) p l a n t s i n each macroplot  were mapped and ranked a c c o r d i n g t o t h e i r  f o l i a r diameter and h e i g h t . Bitterbrush  ( P u r s h i a t r i d e n t a t a . ) p l a n t proved  t o be t o o numerous t o measure i n d i v i d u a l l y ; t h e r e f o r e a. 10 rank s c a l e o f s i z e was used t o r e c o r d t h i s s p e c i e s i n the  macroplot.  15 The u n d e r s t o r y v e g e t a t i o n (dwarf  shrubs,  forbs  and g r a s s e s ) a t each s i t e was d e s c r i b e d u s i n g Daubenmire's  l/10th  meter frame method (Daubenmire,  were counted i n each m a c r o p l o t ,  1959).  F o r t y frames  20 on each s i d e o f t h e ex-  c l o s u r e , p a r a l l e l i n g the contour. C.  Determination  of Characteristic  Stand Age  The assessment o f age o f a stand o f t r e e s o r an open s e r a i community i s n o t a s i m p l e procedure.  While the  t r e e s a t a p a r t i c u l a r s i t e may be, i n t h e main, 50 o l d , t h e d i s t u r b a n c e which l e d t o t h e e s t a b l i s h m e n t  years o f the  s t a n d i n t h e f i r s t p l a c e , may have o c c u r r e d many y e a r s previously.  F o r example, open s e r a i communities on t h e  southwest s i d e o f Premier Ridge a r e t h e r e s u l t o f l o g g i n g which o c c u r r e d about 1910, erated t o f o r e s t .  b u t they have n o t y e t regen-  Thus, w h i l e t h e i r s u c c e s s i o n a l age i s  about 60 y e a r s , t h e i r age i n terms o f f o r e s t  succession i s  zero. The  terms s u c c e s s i o n a l age, c h a r a c t e r i s t i c  age and premodal age, a r e used I n t e r c h a n g e a b l y  stand-  i n this  text,  and r e f e r t o t h e e a r l i e s t p o i n t o f I n f l e c t i o n o f t h e peak on a g r a p h , w h i c h r e p r e s e n t s t h e m a j o r i t y o f t h e t r e e s I n the s t a n d .  The u s e o f a premodal age p e r m i t s  t o be made from t h e time a major e n v i r o n m e n t a l occurred.  predictions; disturbance  F i g u r e 3 shows a graph o f t h e t r e e s found i n one  F i g u r e 3-  1969  I l l u s t r a t i o n of the d e t e r m i n a t i o n of c h a r a c t e r i s t i c stand age. The t r e e s are grouped i n t o age c l a s s e s (each c o n t a i n i n g 5 year c l a s s e s ) and p l o t t e d on a graph. The p o i n t of i n f l e c t i o n of that peak which represents tne D u l k of the t r e e s i s taken as the date at which the stand was i n i t i a t e d . The c h a r a c t e r i s t i c stand age of t h i s example i s 6 5 y e a r s .  Age  Class  1904  17  m a c r o p l o t , i l l u s t r a t i n g the d e t e r m i n a t i o n o f c h a r a c t e r istic  The t r e e s were grouped I n t o 5 y e a r  s t a n d age.  v a l s or c l a s s e s and p l o t t e d a g a i n s t t i m e .  inter-  Most o f the t r e e s  a r e r e p r e s e n t e d by a l a r g e peak, and the e a r l i e s t p o i n t o f i n f l e c t i o n of t h i s peak i s t h e " c h a r a c t e r i s t i c age" o f t h e site. D.  Annual P r o d u c t i v i t y Assessments (Net p r o d u c t i v i t y o f B l i s s and  Westlake)  To f a c i l i t a t e p r o d u c t i v i t y assessments, v e g e t a t i o n a t each s i t e was  the  divided into s i x categories;  ( l ) t r e e s , ( 2 ) l a r g e s h r u b s , ( 3 ) dwarf s h r u b s ,  (4) forbs,  (5) grasses, (6) bearberry. (l)  Trees The a n n u a l p r o d u c t i v i t y o f the t r e e s was  derived  i n crude terms by c a l c u l a t i n g t h e s t a n d i n g volume o f t i m b e r i n each m a c r o p l o t i s t i c stand  and d i v i d i n g t h i s f i g u r e by t h e c h a r a c t e r -  age.  The volume o f each t r e e was  c a l c u l a t e d u s i n g the  f o r m u l a (Smith and Breadon- 1 9 6 4 ) 1.  V = a + bH B  where V a b B H  = = = = =  The volume increment per y e a r was  volume i n f t . 3 species coefficent 1  b a s a l a r e a at- DBH height of t r e e calculated using  the f o r m u l a 2.  p  s  jr ]/ ~T~*  where *P = i n c r e m e n t / y e a r A = c h a r a c t e r i s t i c stand age  18 (2)  B i t t e r b r u s h and S o a p o i a l l i e The a n n u a l p r o d u c t i v i t y o f b i t t e r b r u s h and  s o a p o i a l l i e was determined by subsampling  representative  p l a n t s which had been p r e v i o u s l y mapped i n t h e m a c r o p l o t and a s s i g n e d a s i z e c a t e g o r y . by Q u a d v l e i g  A s i m i l a r method was used  (1968).  Two r e p r e s e n t a t i v e s i z e s o a p o i a l l i e p l a n t s were s e l e c t e d a t random (from a l i s t ranked a c c o r d i n g t o s i z e ) and c u t down a t ground  level.  The c u r r e n t y e a r ' s t w i g s  and a l l t h e l e a v e s on t h e p l a n t were removed and s t o r e d In paper bags.  The r e m a i n i n g p o r t i o n o f t h e p l a n t (wood  o l d e r than 1 y r . ) was a i r - d r i e d on t h e open range f o r 2 weeks.  A t t h i s t i m e , t h e p l a n t was weighed and a s e c t i o n  was c u t from t h e base t o age t h e p l a n t .  These s e c t i o n s  were sanded smooth and examined under a low power m i c r o s c o p e ; l i g h t o i l was used t o f a c i l i t a t e t h e c o u n t i n g o f a n n u a l rings.. To d e t e r m i n e t h e s i z e o f each p l a n t , t h e f o l l o w i n g f o r m u l a was used Crude Volume  =  3.l4 x r  2  x h  where r = r a d i u s o f p l a n t a.t ground l e v e l h = t o t a l height of plant The crude volume f o r a l l t h e s o a p o i a l l i e p l a n t s i n each m a c r o p l o t was d e t e r m i n e d .  The a n n u a l p r o d u c t i v i t y  (annual t w i g s p l u s a l l l e a v e s on t h e p l a n t ) was determined  19 by o v e n - d r y i n g t h e c u r r e n t t w i g s and l e a v e s a t 50° C t o constant weight.  F o r each p l a n t , and f o r each s i t e , an  i n d e x o f t h e weight o f t w i g s and l e a v e s produced a n n u a l l y p e r c u b i c f o o t ( o f crude volume) was c a l c u l a t e d .  The t o t a l  crude volume m u l t i p l i e d by t h e average weight o f a n n u a l twigs and l e a v e s y i e l d e d a t o t a l a n n u a l p r o d u c t i v i t y for s o a p o i a l l i e at that s i t e .  figure  A l l p l a n t s were sampled i n  August 1 9 6 9 when t w i g e l o n g a t i o n had ceased. The b i t t e r b r u s h p l a n t s i n t h e m a c r o p l o t s proved t o be t o o numerous t o c o u n t , hence a s i z e c l a s s system was adopted, employing a 10 rank s c a l e .  R e p r e s e n t a t i v e , randomly  s e l e c t e d p l a n t s i n each m a c r o p l o t were c u t a t ground  level  and t h e i r c u r r e n t t w i g s and a t t a c h e d l e a v e s were removed. The l e a v e s on t h e r e m a i n i n g p o r t i o n o f t h e - p l a n t (secondary wood) were n o t c o l l e c t e d .  The p l a n t s were then d r i e d on t h e  open range f o r two weeks.  At t h e end o f t h i s p e r i o d t h e o l d  wood was weighed and a s e c t i o n was removed from t h e base o f the p l a n t f o r a g i n g . The t o t a l m a c r o p l o t p r o d u c t i v i t y o f b i t t e r b r u s h was determined by m u l t i p l y i n g t h e average a n n u a l weight o f oven d r i e d t w i g s and l e a v e s f o r each s i z e c l a s s by t h e number o f plants i n that s i z e c l a s s .  I n summary, t h e s e t o t a l s  a t o t a l weight f o r t h a t s i t e . sampled  produced  A l l b i t t e r b r u s h p l a n t s were  i n August when a n n u a l t w i g growth had ceased. B i t t e r b r u s h and s o a p o i a l l i e were not sampled  from  20  w i t h i n t h e e x c l o s u r e ; s i z e removal o f such l a r g e components of  t h e v e g e t a t i o n c o u l d s e v e r e l y a l t e r any changes  i n the  community a f f o r d e d hy t h e i r p r o t e c t i o n from g r a z i n g . (3)  G r a s s e s , f o r b s and dwarf shrubs The g r a s s e s , f o r b s and.dwarf  shrubs were c l i p p e d  from one meter q u a d r a t s w h i c h l a y w i t h i n t h e e x c l o s u r e fence. 1968  The q u a d r a t s were p r e - c l i p p e d i n t h e l a t e f a l l o f  and were c l i p p e d t h r e e t i m e s d u r i n g 1 9 6 9 ; t h e s e c l i p p i n g  p e r i o d s were June 2 - 7 , J u l y 23 - 27 and October 4 - 9 . June c l i p o c c u r r e d d u r i n g t h e growing season, t h e J u l y  The  clip  f o l l o w e d mid-summer dormancy o f t h e g r a s s e s , and t h e October c l i p preceded permanent w i n t e r snows.  At each c l i p p i n g d a t e ,  6 meter q u a d r a t s were c l i p p e d a t each s i t e ;  t h e t h r e e com-  ponents o f t h e v e g e t a t i o n were c o l l e c t e d i n s e p a r a t e bags. These samples were a i r - d r i e d i n t h e f i e l d and t h e n o v e n - d r i e d in a forced-air drier at 5 0 ° C u n t i l  c o n s t a n t weight was  achieved. Unless otherwise noted, the y i e l d f i g u r e s represent the  J u l y c l i p when t h e y p e r t a i n t o g r a s s , f o r b o r dwarf shrub  material. (4)  Bearberry Bearberry or k i n n i k i n n i k (Arctostaphylos u v a - u r s i )  was sampled on 4 t o 6 one-meter square q u a d r a t s o u t s i d e t h e e x c l o s u r e i n t h e month o f August.  A l l the bearberry i n the  21 quadrat was removed; when a runner c r o s s e d t h e quadrat frame i t was c u t a t t h a t p o i n t . from o l d e r growth. to a constant  New growth was  separated  These samples were o v e n - d r i e d a t 5 0 ° C  weight.  The f l o r i s t i c and p r o d u c t i v i t y d a t a have been p r e s e n t e d i n g r a p h i c form i n t h i s t e x t .  The c u r v e s on  t h e s e graphs a r e r e p r e s e n t a t i v e o f the t r e n d o f t h e d a t a , and s h o u l d n o t be i n t e r p r e t e d as a l e a s t squares  fit.  22 I I I OBSERVATIONS AND RESULTS A.  Site Description S i x t e e n non-randomly l o c a t e d s i t e s were s e l e c t e d  f o r i n t e n s i v e study.  These i n c l u d e d one n a t u r a l  grassland,  n i n e f o r e s t e d a r e a s and f i v e a r e a s which once were f o r e s t e d hut which have f a i l e d t o r e g e n e r a t e f o l l o w i n g l o g g i n g  and/or  burning. Most o f t h e s i t e s ( t e n ) were l o c a t e d on P r e m i e r Ridge on communities used by w i l d and domestic u n g u l a t e s . The  t h r e e open s i t e s ( u n f o r e s t e d ) on P r e m i e r Ridge i n -  c l u d e d a r e a s l i g h t l y , m o d e r a t e l y and h e a v i l y used by domestic cattle.  H i s t o r i c a l l y , t h e s e s i t e s compare t o t h e r e s t o f the  s i t e s on P r e m i e r .  Generally  t h e s i t e s a r e named a f t e r a  c o n s p i c u o u s element o f t h e i r v e g e t a t i o n  o r by t h e i r l o c a t i o n .  Timbered s i t e s u s u a l l y b e a r t h e name and some rough i n d i c a t i o n of the maturity  o f t h e i r dominant t r e e s p e c i e s .  Open  s e r a i s i t e s ( b e i n g t r e e l e s s ) a r e named a f t e r a shrub o r g r a s s species. The  s i t e s a r e n o t d i r e c t l y comparable t o t h o s e on  Premier Ridge because t h e y r e f l e c t t h e e f f e c t o f e l e v a t i o n . S i n c e w i l d u n g u l a t e s may f o r a g e on t h e east w a l l o f t h e t r e n c h below  6,000 f t .  i n mild winters  and d u r i n g  e a r l y f a l l , a knowledge o f t h e s p e c i e s  l a t e s p r i n g and  c o m p o s i t i o n and p r o -  d u c t i v i t y o f t h e s e a r e a s , e s p e c i a l l y f o l l o w i n g f i r e s and logging, i s pertinent.  23 1.  Skookumchuck P r a i r i e N a t u r a l G r a s s l a n d T h i s s i t e I s the o n l y n a t u r a l g r a s s l a n d p l o t In  the s e r i e s .  I t I s r e p r e s e n t a t i v e o f the l i m i t e d  and  s c a t t e r e d acreage o f n a t u r a l g r a s s l a n d s which dot the f l o o r of  the Rocky Mountain Trench.  used h e a v i l y by domestic v e g e t a t i o n remains.  These g r a s s l a n d s have "been  s t o c k and v e r y l i t t l e o f the p r i s t i n e  The d a t a used i n t h i s s t u d y were d e r i v e d  from an e x c l o s u r e b u i l t i n 1952  on t h e Skookumchuck P r a i r i e  by the B r i t i s h Columbia F o r e s t S e r v i c e . t a t i o n has responded w e l l t o t h e 17 g r a z i n g and i s now  The n a t u r a l vege-  y e a r s o f p r o t e c t i o n from  f a i r l y r e p r e s e n t a t i v e o f the c l i m a x g r a s s -  lands o f the a r e a .  The community dominants a r e  wheatgrass and rough f e s c u e which occupy 63% cover, r e s p e c t i v e l y .  Junegrass  8% o f the ground s u r f a c e .  bluebunch  and 9% o f t h e  ( K o e l e r i a c r i s t a t a ) covers  B l u e g r a s s (Poa spp. ) and  needle-  g r a s s ( S t i p a spp.) were dominants on the s i t e p r i o r t o the c o n s t r u c t i o n of the e x c l o s u r e .  Both genera have been a l l  but e l i m i n a t e d from the e x c l o s u r e .  No shrubs o r t r e e s a r e  p r e s e n t but ponderosa p i n e o c c u r s nearby on the g r a v e l l y , v e r y porous s o i l which c h a r a c t e r i z e s the Skookumchuck Prairie.  The t o t a l ground c o v e r by g r a s s e s was  o c c u p i e d a t o t a l cover of 6%, the p r i n c i p a l . f o r b  {3%)  80$.  Forbs  p h l o x ( P h l o x ca e s p i t o s a ) was  but n i n e o t h e r s p e c i e s were r e c o r d e d .  An u n p r o t e c t e d a r e a a d j a c e n t t o but o u t s i d e the  24  F i g u r e 4.  The Skookumchuck P r a i r i e , a n a t u r a l g r a s s l a n d .  25 e x c l o s u r e f e n c e was a l s o sampled.  Junegrass was  abundant s p e c i e s o c c u p y i n g a c o v e r o f 16$. b l u e g r a s s o c c u p i e d 12%  and 3% r e s p e c t i v e l y .  nant bluebunch wheatgrass p r e s e n t i n t r a c e amounts. o u t s i d e the p l o t was  k0%.  c o v e r was  t h e most  Needlegrass  and  The once domi-  10% and rough f e s c u e  The t o t a l ground  was  c o v e r by g r a s s e s  Forbs were common, e l e v e n s p e c i e s  being recorded, pussytoes  ( A n t e n n a r i a p a r i i f l o r a ) and  flea-  bane ( E r i g e r o n l i n e a r i s ) were the most abundant s p e c i e s h a v i n g ground  c o v e r s o f 2% and 3% r e s p e c t i v e l y .  Skookumchuck P r a i r i e p l o t i s shown I n F i g u r e 2.  Premier Ridge N o n - f o r e s t e d  The  4.  Sites  Mature c l i m a x montane f o r e s t p r e v i o u s l y o c c u p i e d the t h r e e n o n - f o r e s t e d s i t e s on Premier Ridge. was  Douglas f i r  t h e p r i n c i p a l s p e c i e s and stumps of t h i s s p e c i e s w i t h  b a r k a t t a c h e d , remained decay.  i n t h e a r e a , i n v a r i o u s s t a g e s of  The removal o f the f o r e s t and t h e t r e e canopy has  g i v e n r i s e t o widespread  open, s e r a i , n o n - f o r e s t e d  P r e v i o u s l y more w i d e s p r e a d , t h e s e communities  communities.  are l a r g e l y  now  c o n f i n e d t o the south and southwestern s l o p e s o f Premier Ridge. a-  Bluegrass-Needlegrass  Site  This s i t e i s subjected to the heaviest g r a z i n g p r e s s u r e (by domestic s t o c k ) o f a l l the s i t e s on Ridge.  Premier  A d j a c e n t t o A l k a l i Lake, one o f the main water  sources f o r domestic by c a t t l e from May  s t o c k , t h i s community i s h e a v i l y grazed  1 t o the l a t e f a l l .  Kentucky  bluegrass  F i g u r e 5.  The b l u e g r a s s - n e e d l e g r a s s p l o t , l o c a t e d n e a r A l k a l i Lake. N o t e t h e stumps o f t h e p r e v i o u s f o r e s t and t h e "weedy" i n d i c a t o r s p e c i e s o f overgrazing i n the foreground.  Figure 6.  The b l u e g r a s s - n e e d l e g r a s s e x c l o s u r e . reduced c a r r y o v e r o u t s i d e the f e n c e .  Notice  the  28  (Poa p r a t e n s l s ) and Canada b l u e g r a s s (Poa compressa) were abundant a t t h i s s i t e , f o r m i n g a t o t a l o f 2 2 $ o f t h e herbaceous c o v e r .  Junegrass and downy brome (Bromus  tectorum)  were a l s o common c o v e r i n g 1 1 $ and 8 $ o f t h e ground s u r f a c e respectively.  Bluebunch wheatgrass ( c o v e r 2 $ ) and n e e d l e -  g r a s s ( c o v e r 3 $ ) were p r e s e n t i n l e s s e r q u a n t i t i e s . teen s p e c i e s o f f o r b s were r e c o r d e d a t t h i s ,sit.e. a c h i e v e d a ground c o v e r g r e a t e r than 2 $ .  SevenNo s p e c i e s  Shrubs were p r e v a -  l e n t , b i t t e r b r u s h b e i n g t h e most abundant w i t h a ground c o y e r of 1 7 $ .  Saskatoon  ( A m e l a n c h i e r a l n l f o l l a ) covered 4 $ w h i l e  f l a t - t o p s p i r a e a ( S p i r a e a l u c i d a ) covered 2 $ .  Bearberry  was abundant, c o v e r i n g 1 2 $ o f t h e ground s u r f a c e . b.  Bitterbrush Site  . ; :  T h i s a r e a i s t h e second open s i t e s .  i n the s e r i e s of unforested  Located about 3 / 8 mi., from A l k a l i Lake, i t r e -  c e i v e s moderate t o heavy g r a z i n g p r e s s u r e from  cattle.  Kentucky b l u e g r a s s and Canada b l u e g r a s s a r e t h e most abundant grasses, both species a c h i e v i n g a cover o f 1 7 $ . was  a l s o common, c o v e r i n g l 4 $ .  Downy brome  Junegrass was l e s s common,  c o v e r i n g 2 $ , w h i l e b l u e b r u n c h wheatgrass and n e e d l e g r a s s were p r e s e n t i n t r a c e amounts ( c o v e r l e s s than 1 $ ) . Twenty-two s p e c i e s o f f o r b s were r e c o r d e d . r o o t ( B a l s a m o r h l z a s a g i t t a t a ) covered  Balsam  1 0 $ , Oyster p l a n t  (Tragopogon d u b i u s ) covered 1 $ , showy a s t e r ( A s t e r c o n s p l c u u s  29  F i g u r e 7.  The b i t t e r b r u s h s i t e . i n t h e background.  The e x c l o s u r e  can be seen  Figure 8.  A c l o s e u p of the  bitterbrush exclosure.  31  covered 4 $ . The t o t a l c o v e r by f o r b s a t t h i s s i t e was 3 4 $ . Shrubs were v e r y abundant, b i t t e r b r u s h dominated w i t h a ground  the s i t e  c o v e r o f 2 5 $ , saskatoon covered 2 $ , w h i l e  s p i r a e a covered 2 $ . B e a r b e r r y was p r e s e n t i n t r a c e amounts. c.  The R e l i c t Bluebunch Wheatgrass S i t e  T h i s s i t e i s t h e t h i r d i n t h e open u n f o r e s t e d series.  S i t u a t e d on a s t e e p s l o p e about two m i l e s from  the n e a r e s t water s o u r c e , t h i s a r e a r e c e i v e s a l m o s t no g r a z i n g from domestic s t o c k .  I t I s w e l l used by w i n t e r i n g  b i g h o r n sheep and mule d e e r .  Use by e l k i s l i g h t .  Bluebunch wheatgrass 5 1 $ o f t h e ground  surface.  dominates t h e s i t e , c o v e r i n g  Junegrass i s a l s o common,  c o v e r i n g 9 $ , a t r a c e o f downy brome was r e c o r d e d . cover by g r a s s s p e c i e s was 6 0 $ .  Total  The most abundant f o r b was  balsam r o o t w i t h a c o v e r o f 3 $ . Pour o t h e r f o r b s were r e corded i n t r a c e amounts.  T o t a l c o v e r by f o r b s was 4 $ .  Shrubs were n o t abundant a t t h i s s i t e . 4$,  Bitterbrush  covered  s a s k a t o o n o c c u p i e d 2 $ and r o s e (Rosa spp. ) covered 3 $ .  T o t a l c o v e r by shrubs was 9 $ . 3.  Premier Ridge F o r e s t e d S i t e a.  The Young Douglas F i r S i t e  T h i s p l o t i s s i t u a t e d i n a stand o f mature t i m b e r which was s e l e c t i v e l y logged about 1 9 1 0 . Some t r e e s were cut. i n r e c e n t y e a r s .  The stand p r e s e n t l y i s composed  l a r g e l y o f young f i r t r e e s from 3 t o 15 f t . i n h e i g h t , h u t  32  F i g u r e 9'.  The r e l i c t bluebunch-wheatgrass s i t e . Steepness of s l o p e has a l l o w e d t h e s e r i d g e s t o escape the heavy g r a z i n g which i s c h a r a c t e r i s t i c o f t h e lower a r e a s i n t h i s photograph.  33  a few mature t r e e s remain on t h e s i t e .  While the area I s  probably not r e p r e s e n t a t i v e of a c l e a r - c u t logging p r a c t i c e , no s i t e s were found which c o n t a i n e d v e r y young f i r s t a n d s . Most o f t h e mature Douglas f i r was removed from t h e r i d g e e a r l y i n t h e t w e n t i e t h c e n t u r y and r e g e n e r a t i o n e i t h e r commenced i m m e d i a t e l y o r has been " s t a l l e d " by c l i m a t i c and g r a z i n g f a c t o r s . The young f i r s t a n d c o n t a i n e d 1 9 3 0 stems p e r a c r e and had a f o r e s t canopy c o v e r o f 2 0 $ . 22 y e a r s .  The pre-modal age was  A few l a r c h and l o d g e p o l e p i n e were p r e s e n t a t t h i s  s i t e , b u t ponderosa p i n e was absent.  The g r a s s component o f  the u n d e r s t o r y was l a r g e l y composed o f p i n e g r a s s ( C a l a m a g r o s t l s rub esc ens) which had a ground c o v e r o f 4 2 $ .  Rough fescue,  was a l s o abundant a t 1 1 $ and j u n e g r a s s covered o n l y 1 , 2 $ . The t o t a l c o v e r by g r a s s s p e c i e s was 5 4 $ .  F i f t e e n species  o f f o r b s were r e c o r d e d , t h e most abundant b e i n g w i l d b e r r y ( F r a g a r i a g l a u c a ) and w h i t e p u s s y t o e s . by f o r b s was 1 5 $ .  straw-  The t o t a l cover-  Shrubs were common, s a s k a t o o n covered 7 $ ,  s p i r a e a 4 $ , b i t t e r b r u s h , s o a p a l a l l i e and r o s e t o g e t h e r covered 1 $ .  B e a r b e r r y was v e r y common, o c c u p y i n g 1 7 $ and  making up one h a l f o f t h e t o t a l shrub cover o f 33$. b.  The Middle-aged  Douglas F i r S i t e  T h i s s i t e had a. f o r e s t canopy c o v e r o f 5 6 $ and a pre-modal age o f 5 5 y e a r s .  However, l o g g i n g d u r i n g t h e summer  o f 1969 removed s e v e r a l mature t r e e s from t h i s s i t e .  T h i s had  F i g u r e 10.  Figure 11.  R e g e n e r a t i o n on t h e steep western a s p e c t s has been slow. T h i s s i t e was cut about 1 9 1 5 -  The " t e r r a c e " a r e a . o f Premier R i d g e . Note the r a p i d , widespread r e g e n e r a t i o n o f young trees.  Figure 1 2 .  The young Douglas f i r  site.  36  l i t t l e e f f e c t on t h e y i e l d s r e c o r d e d d u r i n g t h i s  study.  There were 6 0 5 stems p e r a c r e a t t h e s i t e , most o f which were Douglas f i r , h u t one l a r c h and s e v e r a l ponderosa p i n e t r e e s were a l s o p r e s e n t .  P i n e g r a s s dominated t h e  s p a r s e u n d e r s t o r y community p r e s e n t a t t h i s s i t e , w i t h a ground cover o f 2 9 $ .  Bluebunch wheatgrass,  j u n e g r a s s and  needlegra.ss were p r e s e n t I n v e r y s m a l l q u a n t i t i e s . b l u e g r a s s s p e c i e s were p r e s e n t . by g r a s s e s was 46$.  The t o t a l ground  No cbver  F i f t e e n s p e c i e s o f f o r b s were r e -  c o r d e d , b u t they t o t a l l e d o n l y 1 7 $ ground c o v e r .  Penstemon  (Penstemon s p p . ) , w i l d s t r a w b e r r y , t i m b e r m i l k v e t c h ( A s t r a g a l u s m i s e r v a r . s e r o t i n u s ) and yarrow m i l l e f o l i u m ) were t h e most common.  (Achillea  The r a p i d l y  developing  f o r e s t canopy was p r o b a b l y r e s p o n s i b l e f o r t h e dead and t h i n l y developed  shrubs a t t h i s s i t e .  B i t t e r b r u s h covered  o n l y 3 $ , s p i r a e a 5 $ , s a s k a t o o n 7 $ and b e a r b e r r y 2 $ .  Total  shrub cover was 1 8 $ . c.  The Mature Douglas F i r S i t e  T h i s was t h e o n l y p l o t which was n o t e s t a b l i s h e d on a south o r southwest s l o p e .  The o n l y r e m a i n i n g stand o f  mature Douglas f i r on Premier Ridge i s l o c a t e d on t h e n o r t h east s l o p e o f t h e r i d g e .  Since t h i s aspect i s d i s t i n c t l y  more humid than those on which t h e o t h e r p l o t s were l o c a t e d , r i g i d d i r e c t comparisons between them should not be made.  Figure 13.  The middle-aged Douglas f i r s i t e . N o t i c e t h e dead shrubs i n the f o r e g r o u n d .  Figure 14.  The mature  Douglas f i r  site.  39 The a r e a s e l e c t e d f o r s t u d y has a pre-modal age o f 95  years,  and 331  73$.  stems per a c r e , w i t h a f o r e s t canopy c o v e r o f  The o n l y g r a s s p r e s e n t was p i n e g r a s s which had a ground c o v e r o f 43$. amounts.  S i x s p e c i e s o f f o r b s were p r e s e n t i n t r a c e  S p i r a e a was  of the ground,  Oregon grape (Mahonia r e p e n s ) and r o s e were  p r e s e n t i n t r a c e amounts. surface.  26$  t h e most abundant shrub c o v e r i n g  Moss covered 12$ o f the ground  Scattered s o a p o i a l l i e p l a n t s occurred  throughout  the s i t e , u s u a l l y h o l e s i n t h e f o r e s t canopy, d.  Young Ponderosa P i n e S i t e  .  This s i t e i s r e p r e s e n t a t i v e of those stands of t r e e s w h i c h have a r i s e n as a r e s u l t o f t h e l o g g i n g and T h i s stand had 958  which removed the mature t i m b e r .  p e r a c r e and a f o r e s t canopy c o v e r o f 49$. age was  80 years.  1  The  fires  stems  pre-modal  While, t h e s t a n d has more f i r . t r e e s than  p i n e , the p i n e s c u r r e n t l y dominate the f i r .  The  undercover  was. s p a r s e , w i t h p i n e g r a s s as t h e most abundant s p e c i e s c o v e r i n g 29$.  Rough f e s c u e c o v e r e d 5$ and j u n e g r a s s 1$ o f  the ground s u r f a c e .  The t o t a l cover by g r a s s was  35$.  S i x t e e n s p e c i e s o f f o r b s covered a t o t a l o f 10$ o f the ground s u r f a c e .  Nodding o n i o n ( A l l i u m cernuum), w i l d  straw-  b e r r y , balsam r o o t and yarrow were a l l p r e s e n t , c o v e r i n g about 1$ o f t h e ground. t o t a l c o v e r was and s p i r a e a 1$.  12$.  Shrubs were not abundant, t h e i r  Saskatoon  covered 4$,  B e a r b e r r y covered  2$.  bitterbmsh  4$  40  e.  Middle-aged  Thig near no  Alkali  site  Lake.  Is situated  p r e - m o d a l age 49$.  cover, was was  the  the  2 $ and also  4$  the  bluebunch  canopy, Pinegrass  covering 22$.  The  total  ("17$), w h i l e  a  c o v e r was  saskatoon  32$,  covered  half  11$  of  were total  most a b u n d a n t c o v e r i n g  t h e p l a n t s -were t h i n and  shrub  Rough  covers  T h i r t e e n species of forbs covered  Shrubs, were common, b u t  bearberry  forest  are  forest.  T r a c e amounts o f j u n e g r a s s  T i m b e r m i l k v e t c h was  developed.  earlier  wheatgrass are present with  respectively.  knoll  There  T h e r e were 2 6 1 stems p e r a c r e .  recorded.  of 23$.  stand.  e x i s t e n c e o f an  1 0 0 y e a r s , and  was  Site  top o f a d r y  t h e most a b u n d a n t u n d e r s t o r y g r a s s  f e s c u e and  4$  on  Pine  It i s a very uniform  stumps s u g g e s t i n g  The  Ponderosa  14$.  weakly of this  and  being  bitterbrush  ?  f.  Climax  A 280 year  Ponderosa Pine o l d stand  to represent the climax site  had  a c r e , and major  a forest appears  forest  canopy c o v e r  Site  o f p o n d e r o s a p i n e was  chosen  of the t r e n c h f l o o r .  This  o f 38$ w i t h 74  per  t o have been r e l a t i v e l y u n a f f e c t e d by  env i r o nm en t a 1  disturbances i n recent  p r i n c i p a l understory  g r a s s was  june-  1$ and  the  total  5$.  21$ o f the s u r f a c e .  Rough f e s c u e c o v e r e d 36$.  T h i r t e e n species of forbs  Balsam r o o t a t  12$,  of  and  grass  and  timber  .  The  11$  Bluebunch wheatgrass covered  c o v e r by g r a s s was  times.  p i n e g r a s s c o v e r i n g 18$  the s u r f a c e . covered  stems  covered milk  Figure 15.  The young ponderosa p i n e  site.  42  v e t c h a t 4 $ were t h e most prominent  species.  Shrubs were  abundant under t h e r e l a t i v e l y open canopy o f t h e c l i m a x f o r e s t , covering a t o t a l of 35$-  K i n n i k i n n i k covered 1 7 $ ,  b i t t e r b r u s h 1 5 $ , s a s k a t o o n 4 $ and s p i r a e a c o v e r e d 1 $ . g.  The Lodgepole  P i n e Stand  The  l o d g e p o l e p i n e stand on Premier Ridge i s  r e p r e s e n t a t i v e o f r e l a t i v e l y 'uniform stands which on t h e s t u d y a r e a .  -  occur  These stands a r e t h e r e s u l t o f f i r e s  which f o l l o w e d l o g g i n g .  The l o d g e p o l e s i t e on Premier i s  l o c a t e d on a burn w i t h i n t h e c l i m a x ponderosa  pine f o r e s t .  S c a t t e r e d t r e e s from t h e o r i g i n a l f o r e s t s t i l l remain.  The  dense l o d g e p o l e s i t e had a canopy c o v e r o f 7 8 $ and a p r e modal age o f  65  years.  There were  3,459  stems p e r a c r e .  P i n e g r a s s was t h e main u n d e r s t o r y g r a s s w i t h a canopy cover o f 3 9 $ .  Rough f e s c u e had a c o v e r o f 2 $ .  s p e c i e s o f f o r b s covered 1 5 $ . berry.were  Fifteen  Pussytoes and w i l d  straws  t h e most common c o v e r i n g , 2 $ and 1$ r e s p e c t i v e l y .  The shrub c o v e r was 2 0 $ i n t o t a l , b u t appeared  t o be de-  c l i n i n g as s p a r s e o r dead p l a n t s were common.  Kinnikinnik  was  abundant, c o v e r i n g 1 0 $ , s a s k a t o o n covered 7 $ and b i t t e r -  brush 2 $ . 4.  The E s t e l l a Mountain F o r e s t e d . S i t e s The  "Regenerating D o u g l a s . f i r " and t h e " L a r c h "  s i t e s on E s t e l l a Mountain were s e l e c t i v e l y logged about 1952.  These s i t e s a r e r e p r e s e n t a t i v e o f t h e t y p e s o f l o g g i n g  used i n t h e a r e a and i t s subsequent  e f f e c t s on t h e u n d e r s t o r y  43  community.  The r e m a i n i n g t h r e e s i t e s , the s e r a i bluebunch  wheatgrass,  the s e r a i f e s c u e and the l o d g e p o l e a r e a , were  e s t a b l i s h e d on a b u r n which o c c u r r e d i n 193^-  The  s e r a i s i t e s have f a i l e d t o r e g e n e r a t e t o t r e e s .  two  The  lodge-  p o l e s i t e i s r e p r e s e n t a t i v e o f the r e f o r e s t e d a r e a which developed  f o l l o w i n g the f i r e i n the o r i g i n a l stands w h i c h  were Douglas f i r and w h i t e b a r k p i n e ( P l n u s a l b i c a u l i s ) . Ponderosa p i n e i s n e a r l y absent (above  4,000  from t h e w a l l s o f the t r e n c h  f t . ) , Douglas f i r i s p r e v a l e n t , as i s l a r c h , : .  and on the n o r t h and n o r t h e a s t s l o p e s Englemann spruce i s v e r y common. a.  The R e g e n e r a t i n g  Douglas F i r S i t e  The r e g e n e r a t i n g Douglas f i r s i t e a t the 4 , 1 7 0 f t . e l e v a t i o n was  t h i n n e d by s e l e c t i v e l o g g i n g about  1952.  S i t u a t e d on a bench w i t h g r a v e l l y , w e l l - d r a i n e d s o i l , s i t e has a pre-modal age o f 17 y e a r s .  this  However, o l d mature  t r e e s remain a t the s i t e and comprise most o f the p r e s e n t day f o r e s t canopy cover o f 3 5 $ .  Stands which have been  s e l e c t i v e l y logged a r e u s u a l l y d i f f i c u l t t o age.  Con-  s e q u e n t l y , the age has been d e r i v e d from the time o f the l a s t major e n v i r o n m e n t a l d i s t u r b a n c e ( l o g g i n g , i n t h i s case).  There i s no evidence t o suggest  has been burned i n r e c e n t t i m e s .  The  553 stems per a c r e and p i n e g r a s s was  that t h i s  stand  stand d e n s i t y was the most abundant  u n d e r s t o r y g r a s s c o v e r i n g 4 2 $ o f the ground s u r f a c e .  Rough  Figure 1 7 .  A c l o s e - u p o f t h e middle-aged ponderosa p i n e  site.  F i g u r e ].8.  E s t e l l a M o u n t a i n a s s e e n f r o m ttee f l o o r the Rocky M o u n t a i n T r e n c h .  of  Figure 19.  The l o d g e p o l e p i n e s i t e on Premier Ridge. Note the o l d ponderosa p i n e " v e t e r a n s " which s u r v i v e d the f i r e which gave r i s e t o the l o d g e p o l e stand In the background.  47  f e s c u e was  p r e s e n t i n t r a c e amounts, p o s s i b l y r e i n v a d i n g  a f t e r t h e stand was  thinned.  T o t a l g r a s s c o v e r was  42$.  E l e v e n s p e c i e s o f f o r b s were r e c o r d e d ; h e a r t - l e a v e d a r n i c a ( A r n i c a c o r d i f o l i a ) covered 8 $ and t i m b e r m i l k v e t c h covered 6$.  The t o t a l c o v e r by f o r b s was  22$.  Shrubs formed a major  p o r t i o n o f t h e u n d e r s t o r y ; b e a r b e r r y covered l 8 $ , s p i r a e a 12$ and Rocky Mountain j u n i p e r ( J u n i p e r u s scopuiorum) covered 8 $ . b.  The L a r c h S i t e  The  l a r c h s i t e on E s t e l l a Mountain i s l o c a t e d i n  a m o i s t draw a t the  4,220  ft.  elevation.  Logged In  1952  t h i s s i t e i s c u r r e n t l y dominated by l a r c h ; t h e u n d e r s t o r y i s a r a p i d l y d e v e l o p i n g stand o f young Douglas f i r .  The  e x i s t i n g l a r c h t r e e s a r e 6 0 t o 70 f e e t h i g h , have a f o r e s t canopy cover o f 7 2 $ and a pre-modal age of 125 y e a r s .  The  g r a s s u n d e r s t o r y i s dominated by p i n e g r a s s c o v e r i n g 5 2 $ . Ten s p e c i e s o f f o r b s had a t o t a l cover o f 2 6 $ .  Heart-  l e a v e d a r n i c a covered 1 7 $ , w i l d s t r a w b e r r y 2 $ and b e l l s or  western  covered 2 $ .  stenanthium  bronze  (Stenanthium o c c i d e n t a l e )  Shrubs were an i m p o r t a n t component of the  u n d e r s t o r y c o v e r i n g 2 5 $ o f t h e ground s u r f a c e .  Spiraea  12$ and t w i n f l o w e r ( L l n n a c a b o r e a l i s ) 3$ were t h e most common s p e c i e s . c.  The  Lodgepole S i t e  The  l o d g e p o l e s i t e on E s t e l l a . i s r e p r e s e n t a t i v e  F i g u r e 20.  The r e g e n e r a t i n g D o u g l a s f i r s t a n d Mounts i n .  on E s t e l l 8  49  o f t h i c k stands o f l o d g e p o l e p i n e which f o l l o w e d t h e f i r e of  1934.  The e l e v a t i o n o f t h e s i t e i s 5 , 9 8 0 f t ,  and t h e pre-modal age i s 35 y e a r s .  The f o r e s t canopy  c o v e r was 7 1 $ i n t h i s s t a n d which had 1 , 6 3 4 stems p e r acre.  P i n e g r a s s was t h e o n l y g r a s s s p e c i e s p r e s e n t ,  h a v i n g a ground c o v e r o f 2 9 $ .  Twelve s p e c i e s o f f o r b s  covered 3 7 $ . Most abundant were h e a r t - l e a v e d a r n i c a c o v e r i n g 7 $ , a s t e r ( A s t e r c o n s p l c u u s ) c o v e r i n g 1 2 $ . Shrubs o c c u p i e d 2 3 $ o f t h e ground c o v e r ; s p i r a e a and s o a p o l a l l i e were most common w i t h c o v e r s o f 7 $ each.  Bearberry, rose  and t w i n f l o w e r were a l s o p r e s e n t . 5.  E s t e l l a Mountain N o n - f o r e s t e d a.  Sites  S e r a i Fescue S i t e  The s e r a i f e s c u e s i t e on E s t e l l a i s l o c a t e d a t the  5,960  f t elevation.  S t a n d i n g and f a l l e n t r e e s o f t h e  burned w h i t e b a r k p i n e f o r e s t remain a t t h e s i t e . p i n e has f a i l e d t o e s t a b l i s h b u t s e v e r a l w h i t e b a r k s e e d l i n g s were found i n t h e m a c r o p l o t .  Lodgepole pine  The pre-modal age  o f t h i s s i t e i s z e r o , i n terms o f r e f o r e s t a t i o n , however a burn o c c u r r e d 35 y e a r s ago.  The g r a s s community a t t h i s  s i t e i s c u r r e n t l y dominated by rough f e s c u e which has a cover o f 4 l $ .  P i n e g r a s s i s a l s o p r e s e n t , p r o b a b l y as a  r e s u l t of the previous f o r e s t , covering 7 $ .  Canada b l u e g r a s s  and an u n i d e n t i f i e d F e s t u c a spp. were p r e s e n t i n t r a c e  Figure  22.  The l o d g e p o l e p i n e stand on E s t e l l a Mountain. The opening i n the foreground i s the r e s u l t o f t h e road c u t .  52 amounts.  The t o t a l c o v e r b y g r a s s was 48$.  abundant; seventeen  Porbs were  s p e c i e s had a t o t a l c o v e r o f 4l$.  Common s p e c i e s were w h i t e penstemon w i t h 16$ c o v e r , yarrow 6$ and locoweed ( O x y t r o p i s c a m p e s t r i s ) w h i c h covered 3$ of t h e ground s u r f a c e .  Shrubs were n o t abundant  w i t h a t o t a l cover o f 11$; b e a r b e r r y c o v e r i n g 5 $ , was most common, w h i l e s p i r a e a , Rosa spp. and w i l l o w ( S a l i x spp.) were a l s o p r e s e n t . d.  The S e r a i Bluebunch Wheatgrass S i t e  The. s e r a i bluebunch wheatgrass s i t e on E s t e l l a . i s l o c a t e d on a g r a s s y f i n g e r o f v e g e t a t i o n i n t h e lodgep o l e p i n e f o r e s t a t an e l e v a t i o n o f  6,200  f t . Tree r e -  g e n e r a t i o n d i d n o t f o l l o w t h e burn o f 1934 and t h e s i t e i s dominated by rough f e s c u e b u t i s unique because wheatgrass s p e c i e s occupy 6$ c o v e r .  No bluebunch  wheatgrass was  found on t h e lower e l e v a t i o n f e s c u e s i t e , b u t i t o c c u r s on t h e same burn a t an e l e v a t i o n o f  4,500 f t .  Bluegrass  covered 4$ a t t h i s s i t e ; t h e t o t a l c o v e r by g r a s s e s was 33$.  N i n e t e e n s p e c i e s o f f o r b s were r e c o r d e d ,  17$ c o v e r .  Common s p e c i e s were s t o n e c r o p  totalling  (Sedum spp.)  3$ c o v e r , yarrow 2$ c o v e r and n a r r o w - l e a v e d p a r s l e y . (Lomatium t r i t e r n a t u r n ) covered 3$.  No shrubs were found  on t h e s i t e , b u t s c a t t e r e d clumps o f b e a r b e r r y were  Figure  23.  The s e r a i f e s c u e s i t e . N o t i c e the burned stumps o f t h e w h i t e - b a r k p i n e f o r e s t w h i c h e x i s t e d p r i o r t o the 1934 f i r e . This photog r a p h was t a k e n " d o w n h i l l " l o o k i n g t o w a r d the f l o o r of the t r e n c h .  54 observed  i n the v i c i n i t y .  B.  F l o r i s t i c Dynamics  1.  The  Premier Ridge  Sites.  The t h r e e u n f o r e s t e d s i t e s  on Premier were e s t a -  b l i s h e d on two v e g e t a t i o n t y p e s , t h e r e l i c t b l u e b u n c h wheatgrass g r a s s l a n d and t h e b l u e g r a s s - b i t t e r b r u s h community. The wheatgrass g r a s s l a n d was  p r o b a b l y i n i t i a t e d by the r e -  moval o f the t i m b e r from the a l r e a d y f a i r l y open f o r e s t , o f which b l u e b u n c h wheatgrass would have been an member o f t h e u n d e r s t o r y community. f o r e s t has a l l o w e d t h i s  important  The removal o f the  s i t e to s h i f t dynamically  toward  the f l o r i s t i c c h a r a c t e r i s t i c s o f the n a t u r a l g r a s s l a n d In the a r e a . The u n d e r s t o r y o f the b l u e g r a s s - n e e d l e g r a s s  site  and the b i t t e r b r u s h s i t e p r o b a b l y d i d not c o n t a i n any b l u e g r a s s s p e c i e s a t t h e time o f l o g g i n g . p r o x i m i t y of these s i t e s  However, the  relative  (and most o f the b l u e g r a s s -  b i t t e r b r u s h community) t o water and t h e i r  relative  flatness,  p r o b a b l y s u b j e c t e d them to heavy c o n s t a n t g r a z i n g f o l l o w i n g l o g g i n g and the f i r e s which swept the a r e a .  Consequently,  Canada b l u e g r a s s and Kentucky b l u e g r a s s were a b l e t o dominate the s i t e r a t h e r than b l u e b u n c h wheatgrass which would r e q u i r e more time and stantial  development.  lighter  g r a z i n g p r e s s u r e f o r sub- •  55  F i g u r e 24.  The s e r a i b l u e b u n c h w h e a t g r a s s s i t e . The b u r n e d f o r e s t was one o f w h i t e - b a r k p i n e . The living t r e e s i n the p i c t u r e are lodgepole p i n e . Notice t h e e f f e c t o f a s p e c t on t h e p a t t e r n of t h e r e generation .  56  Rough f e s c u e may have been a member o f t h e f o r e s t u n d e r s t o r y , however i t s extreme s e n s i t i v i t y t o heavy g r a z i n g has e f f e c t i v e l y  removed i t from t h e u n f o r e s t e d s i t e s  were s t u d i e d on P r e m i e r R i d g e .  which  The r e l i c t bluebunch wheat-  g r a s s s i t e on P r e m i e r i s t h e s i t e most r e p r e s e n t a t i v e o f the n a t u r e o f t h e s u c c e s s i o n when u n a f f e c t e d by heavy g r a z i n g by domestic, s t o c k .  C o n s e q u e n t l y , t h i s s i t e was  s e l e c t e d t o r e p r e s e n t t h e open u n f o r e s t e d a r e a s o f t h e ridge.  The p l a c e , o f t h e b l u e g r a s s - b i t t e r b r u s h community  and i t s r e l a t i o n s h i p t o t h e f l p r i s t i c dynamics w i l l be d i s c u s s e d i n a l a t e r s e c t i o n on t h e e f f e c t o f g r a z i n g on community c o m p o s i t i o n and p r o d u c t i v i t y . a.  Grasses  The r e l i c t bluebunch wheatgrass i s t i c o f u n f o r e s t e d communities  s i t e i s character-  which developed  following  l o g g i n g and b u r n i n g under a r e l a t i v e l y moderate g r a z i n g regime.  Bluebunch wheatgrass  dominates  ground c o v e r o f about 5 0 $ i s common. o t h e r common g r a s s .  t h e s i t e and a  Junegrass i s t h e o n l y  As r e f o r e s t a t i o n commences an immediate  r e d u c t i o n i n t h e bianchgrasses i s n o t e d ; t h e s e s p e c i e s r e main uncommon o r may c o m p l e t e l y d i s a p p e a r from t h e unders t o r y , u s u a l l y r e a p p e a r i n g i n c l i m a x f o r e s t s as t h e f o r e s t canopy opens.  The l e v e l o f abundance a c h i e v e d i n t h e s e  c l i m a x stands I R about 20$ o f t h a t a c h i e v e d on t h e un-  57  forested  sites.  Junegrass a l s o becomes l e s s abundant as  t h e f o r e s t develops r e a p p e a r i n g i n t h e c l i m a x f o r e s t community, where i t may a c h i e v e 5 0 $ o f i t s former abundance.  P i n e g r a s s i s v e r y uncommon on t h e open s i t e s ,  however i t i n c r e a s e s r a p i d l y as f o r e s t r e g e n e r a t i o n commences. On m o i s t s i t e s p i n e g r a s s may r e a c h a ground c o v e r o f 4 0 $ ' or more i n s p i t e o f a heavy f o r e s t canopy.  The t o t a l  ground c o v e r by a l l s p e c i e s o f g r a s s e s d e c r e a s e s increasing  with  s t a n d age. T a b l e s I and I I and F i g u r e 2 5  d e p i c t t h e t r e n d s o f g r a s s ground c o v e r as c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy c o v e r change, b.  Forbs  The c h a r a c t e r i s t i c s t a n d age and t h e f o r e s t canopy c o v e r seemed t o have no pronounced e f f e c t on t h e total,abundance  o f f o r b s ( F i g s . 26, 27, 28 and 29).  v i d u a l s p e c i e s show s t r o n g p r e f e r e n c e f o r c e r t a i n canopy t y p e s . nodding and 27).  Indi-  forest  Yarrow, sedge (Carex s p p . ) , p u s s y t o e s ,  o n i o n and w i l d s t r a w b e r r y a r e s c i o p h y t e s ( F i g s . 26 Balsam r o o t i s a h e l i o p h y t e w h i l e t i m b e r m i l k  v e t c h seems t o be a s c i o p h y t e ( F i g . 28).  The number o f  f o r b s p e c i e s p r e s e n t a t t h e v a r i o u s s i t e s was r e l a t i v e l y c o n s t a n t , except f o r t h e r e l i c t bluebunch which had o n l y 5 s p e c i e s o f f o r b s .  wheatgrass  In the climax f o r e s t  f o r b s were most common, c o m p r i s i n g 21$ o f t h e ground cover.  site  F i g u r e 25.  The abundance o f s e v e r a l s p e c i e s o f g r a s s e s on Premier Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  m i D itmsm  »  Rough f e s c u e  B v  Pinegrass Bluebunch wheatgrass  50 40 30 20 10  v  i \ a 10 20 30 4o 50 60 70 8o 90 C h a r a c t e r i s t i c Stand  50 40 CD |>  O o  ^  30 20 10  F o r e s t canopy %  o  no Age  130  280  59  Table I  The i n f l u e n c e o f c h a r a c t e r i s t i c stand age on the s p e c i e s dynamics o f the u n d e r s t o r y g r a s s s p e c i e s e x p r e s s e d as p e r c e n t ground c o v e r . F o r e s t stand  0 22  Grass sp. Bluebunch wheatgrass  51 .  Junegrass  ". • 9  Needlegrass  Table I I  100  1  ;8 • 2  4 ... 11 2 1  5 1  .i  280  5.  T  '5 42 29 39  29  43  22  18  54  35  43  28  35  T  Pinegrass T o t a l ground c o v e r by g r a s s e s  80 "95  65  '•••3 .  11  Rough f e s c u e  55  age  60  4l  46  The i n f l u e n c e of f o r e s t canopy cover on the p e r c e n t ground c o v e r of the g r a s s component o f the u n d e r s t o r y % F o r e s t canopy cover  Grass sp. Bluebunch wheatgrass  0  9  Needlegrass  1  5  49  5 1  49  56  4  2  3 8  T  1 43  39  43  4l  42  18  29  22  5 29  54  36  35  28  46  T  Pinegrass T o t a l ground c o v e r by g r a s s spp.  11  38 11 1  51  Rough f e s c u e Junegrass  26  60  71  78  2  6o c.  Shrubs  The abundance o f shrubs on the u n f o r e s t e d s i t e s was v a r i a b l e , and d i r e c t l y r e l a t e d t o g r a z i n g p r e s s u r e . F i g u r e 30  and T a b l e I I I d e p i c t the r e l a t i o n s h i p between  c h a r a c t e r i s t i c s t a n d age and shrub abundance.  Shrubs i n -  c r e a s e d s l i g h t l y as f o r e s t r e g e n e r a t i o n began, dropped o f f i n dense, middle-aged  s t a n d s and began t o r e a p p e a r i n mature  and c l i m a x f o r e s t s . The e f f e c t o f f o r e s t canopy on the p e r c e n t ground c o v e r o f shrubs i s shown i n T a b l e I I I and F i g u r e  30.  Shrubs were v a r i a b l e i n c o v e r on the u n f o r e s t e d s i t e s and I n c r e a s e d s l i g h t l y i n the m i d d l e canopy r a n g e s , but beyond a 50$  canopy c l o s u r e shrubs d e c r e a s e d s h a r p l y , except on  the n o r t h e a s t s l o p e (mature f i r s i t e , 73$  canopy).  B i t t e r b r u s h decreased r a p i d l y w i t h f o r e s t r e g e n e r a t i o n and reappeared i n t h e c l i m a x f o r e s t .  Bearberry,  u s u a l l y p r e s e n t I n v e r y s m a l l amounts I n u n f o r e s t e d s i t e s , i n c r e a s e d s h a r p l y i n middle-aged stands and i n t h e m i d d l e canopy ranges. 2.  Estella a.  Mountain Grasses  The t r e n d s e s t a b l i s h e d f o r t h e P r e m i e r Ridge d a t a appear t o h o l d f o r the E s t e l l a s i t e s .  Rough f e s c u e f r e -  q u e n t l y r e p l a c e s bluebunch wheatgrass as t h e dominant bunchgrass on u n f o r e s t e d s i t e s .  61 F i g u r e 26.  The abundance o f s e v e r a l s p e c i e s o f f o r b s on Premier R i d g e , as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age. o denotes abundance i n n a t u r a l g r a s s l a n d community  4 3 2 1 4 3 2 1  Yarrow  4 3 2 1 CD  > o o  4 3 2 1 4 3 2 1  Wild  Hyi».i».MIwi. I I U I H I . . I I I 1 I H . . .UI..IIII^... •  "I'm,; I mn 1  nii;  Onion  ••  Wild Strawberry  /  4 3 2 1  Penstemori  1—m—1  0  20  -i  4o  1  60  i  1  80  r  1—8—J—rV » *i  100  120  C h a r a c t e r i s t i c Stand Age  280  62  Figure 27.  The abundance o f s e v e r a l s p e c i e s o f f o r b s on P r e m i e r Ridge as i n f l u e n c e d by f o r e s t canopy. o denotes l e v e l i n n a t u r a l g r a s s l a n d  F o r e s t Canopy %  community  63  Figure 28.  The abundance o f t i m b e r m i l k v e t c h and b a l s a m - r o o t on P r e m i e r Ridge as i n f l u e n c e d by f o r e s t canopy.  o denotes l e v e l i n n a t u r a l g r a s s l a n d  community  l4 Timber m i l k  12  vetch  10  8 6 4 2 CD >  o o  12 10  8 6 4 2  T  T  20  30  i 4o  I 50  J  6o  F o r e s t Canopy %  i 70.  1  r  8o  90  64  Figure 29.  The abundance o f f o r b s on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy. o denotes l e v e l i n n a t u r a l g r a s s l a n d community  35 30 25 CD  20  O  15  > o  10  5 T — I — r — i — i  o  20  4o  a — i — n — r  i  6o  8o  Characteristic  IOO  r 120  Stand A g e  r  I 280  65  F i g u r e 3 0 . . The abundance o f dwarf shrubs on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  50 4o 0 > o o  30  10 10  T 0  20  "T" 40  i  \ 60  T 80  Characteristic  T—r .100  Stand  F o r e s t Canopy %  n—1—T/ 120 140  Age  ~T~ 280  T a b l e I I I The abundance o f shrubs on t h e Premier Ridge s i t e s , i n r e l a t i o n t o c h a r a c t e r i s t i c stand age and f o r e s t canopy. C h a r a c t e r i s t i c Stand Age F o r e s t Canopy %  0 0  Spirea Rose  0 0  0 0  1.5 3.0  22 2b  55 5b  2.3  4.4  4.8  2.5  1.0  1.2  65 78  80 49  95 72  1.4  26.3  0.1  Bearberry Bitterbrush Soapolallie T o t a l % cover by shrubs  280 3b 1  1.2  0.6  0.9 0.9  Oregon Grape Saskatoon  100 49  2.0  2.4  3.8  7.1  0.5 11.6  16.9  3.6 25.0 16.6  1.3  7-0 20 2.5  7-3  4.3  11.2  3.7  10.1  2.2  17.1  l6.5  2.2  3-7  0.4  1.0 8.6 29.4 4 l . 8 34.7  15.0  1.6 17.5  20.7  11.6  28.1  31-5  35.8  67 F i g u r e 31 shows the e f f e c t o f c h a r a c t e r i s t i c stand age  on the s p e c i e s abundance of g r a s s e s .  On most  u n f o r e s t e d a r e a s , a bunchgrass dominates the community ( 2 0 - k0%  cover).  Pinegrass  i s present  i n t r a c e amounts  on these open a r e a s and  i n c r e a s e s i n abundance as f o r e s t  r e g e n e r a t i o n commences.  The bunchgrasses a r e reduced i n  abundance or d i s a p p e a r s o l e grass present The  completely.  P i n e g r a s s may  be  i n mature f o r e s t s t a n d s .  e f f e c t o f f o r e s t canopy on g r a s s abundance  on E s t e l l a Mountain i s shown i n FIgtire 3 1 .  The  pa.ttern  i s s i m i l a r t o the one d e s c r i b e d f o r c h a r a c t e r i s t i c age.  The  the  stand  time r e q u i r e d f o r the f o r e s t t o d e v e l o p on  Estella,  i s c o n s i d e r a b l y l e s s than i s r e q u i r e d on Premier Ridge. b.  Forbs  The abundance o f f o r b s on E s t e l l a Mountain, as assessed  by ground c o v e r , f o l l o w s a p a t t e r n s i m i l a r to t h a t  found on P r e m i e r Ridge.  C h a r a c t e r i s t i c stand age and f o r e s t  canopy have l i t t l e e f f e c t on t o t a l f o r b abundance ( F i g . 3 2 ) . T h i r t y - n i n e s p e c i e s of f o r b s were r e c o r d e d a t the Estella sites.  The  highest s i t e ,  6,200  g r e a t e s t number of f o r b s p e c i e s , 1 9 . s u f f i c i e n t numberof s i t e s on  five  f t . a l s o had  There was  not  the a  E s t e l l a Mountain t o a s c e r t a i n  which f o r b s were h e l i o p h y t e s and which were s c i o p h y t e s . c.  Shrubs  There was  no d e f i n i t e t r e n d i n the shrub d a t a when  68  Figure.31.  The abundance o f s e v e r a l s p e c i e s o f g r a s s e s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  Rough f e s c u e B B Pinegrass v Bluebunch wheatgrass  69  T a b l e IV  The abundance o f s e v e r a l s p e c i e s o f measured by p e r c e n t ground c o v e r on Mountain. Tabulated w i t h reference c h a r a c t e r i s t i c s t a n d age and f o r e s t  C h a r a c t e r i s t i c Stand F o r e s t Canopy Rough f e s c u e  Age  0 0 40.9  Bluebunch wheatgrass 6.9  Bluegrass  0.1  by  25 35  22.3  35  71  .125.  72  0.5  6.2  Pinegrass  T o t a l % cover grasses  0 0  g r a s s e s as Estella to canopy.  48.3  41.7  29.0  51.7  42.2  29.0  51.7  4.4 32.9  70  T a b l e V. The abundance o f f o r b s as measured by p e r c e n t ground c o v e r on E s t e l l a M o u n t a i n , r e c o r d e d re-.--. l a t i v e t o c h a r a c t e r i s t i c s t a n d age and f o r e s t . canopy. : C h a r a c t e r i s t i c Stand Age F o r e s t Canopy  0 / 0  .  0 0  25 35  35 71  1  T  Pussytoes Fireweed  T  Arnica c o r d i f o l i a  T  Sedges  T  Mountain  1.7  T  8.1  6.7  1.9  3.0  1.8  P y r o l a secunda  Yarrow Penstemon p r o c e r u s Locoweed  16.8  3.2  death  Hedysarum s u l p h u r esc ens  125 72  .  3.3  LO  5.7  1.6  15.6  1.2  3.4  Timber m i l k v e t c h  1.6 T  T  6.2  T  1.7  T  T  Wild strawberry  1.9  T  Bronze b e l l s  1.6  Twinflower  2.7 3.7  Stonecrop  1.1  Nodding o n i o n Narrow l e a v e d p a r s l e y  2.5  Mountain p h a c e l i a  1.5  Aster conspicuus  8.3  Number o f o t h e r s p e c i e s present i n t r a c e 1.0) abundance  7  forbs  . Ground c o v e r by  2.0  10  =4  41.8 18.9 22.4  12.0  2 36.5  1.9  5 38.2  71  compared w i t h c h a r a c t e r i s t i c stand age and f o r e s t Bitterbrush  canopy.  i s not found on t h e E s t e l l a s i t e s , b e i n g r e -  s t r i c t e d t o e l e v a t i o n s below  4,000  ft.  In g e n e r a l ,  shrub abundance was about t h e same magnitude on Premier Ridge.  total  as t h a t found  The abundance o f shrubs on E s t e l l a  Mountain i s l i s t e d i n T a b l e V I . Table V I .  S t a t i s t i c s f o r Shrub Abundance on E s t e l l a Mountain Years  C h a r a c t e r i s t i c Stand F o r e s t Canopy  Age  0 0  0 0  25 35  Spiraea  2.7  -  12.0  6.9  11.7  Rose  1.8  8.7  0.1  1.0  1.5  Bearberry  5.2  -  18.1  4.1  0.1  6.9  Soapalallie  35 71  125 72  Unknown sp.  7.0  T o t a l shrub c o v e r  C.  Productivity  1.  Premier Ridge a.  Grass  9.7  8.7  30.3  18.9  20.2  Productivity  The t o t a l p r o d u c t i v i t y o f g r a s s was h i g h e s t on the open s i t e s and lowest on t h o s e s i t e s w i t h dense c a n o p i e s and r a p i d l y growing t r e e s .  The e f f e c t which f o r e s t r e -  g e n e r a t i o n has on g r a s s p r o d u c t i o n i s e v i d e n t i n F i g u r e 3 3 .  72  Figure 32.  The abundance o f f o r b s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  50 40  >  O O  30  J  20 10  0  T — r  20  u 4o  i  i—T~T—r 6o  280  8o  Characteristic  Stand Age  F o r e s t Canopy %  73  Average p r o d u c t i o n o f g r a s s e s on the t h r e e open s i t e s 53 gm/m ( 4 7 2 T b / A C ) .  was  Twenty y e a r s a f t e r the i n i t i a l  2  stages  o f f o r e s t r e g e n e r a t i o n , g r a s s p r o d u c t i v i t y dropped t o 6 2 $ o f i t s former l e v e l .  F i f t y - f i v e years f o l l o w i n g  forest  r e g e n e r a t i o n o n l y 2 5 $ of the open a r e a p r o d u c t i v i t y i s a c h i e v e d by g r a s s e s . " P r o d u c t i o n o f g r a s s remains low, the stand b e g i n s  to,thin.  duction r i s e s s l i g h t l y .  As the f o r e s t ages, g r a s s  pro-  In t h e s e c l i m a x f o r e s t stands  4 0 $ o f the g r a s s p r o d u c t i o n o f open areas may  be  until  about  attained.  A s i m i l a r t r e n d i s noted when f o r e s t canopy cover i s used as a v a r i a b l e i n measuring g r a s s (Fig-  33).  productivity  At a f o r e s t canopy o f 2 6 $ , g r a s s  productivity  dropped to 5 1 $ of the open areas and a t a f o r e s t canopy o f 5 0 $ p r o d u c t i o n dropped t o 3 8 $ . increasing founding  S p e c i e s changes occur w i t h  shade and must t h e r e f o r e be regarded  as a con-  factor. b.  Forb  Productivity  Forb abundance i s o f t e n reduced i n c l i m a x g r a s s lands and g r e a t l y i n c r e a s e s i n secondary g r a z i n g s u c c e s s i o n s . D e s p i t e d i f f i c u l t i e s i n a n a l y s i n g f o r b performace and ence i n f l o r i s t i c s t u d i e s , warrants  special  occurr-  t h e i r importance t o g r a z e r s  categorization.  F i g u r e 34 r e f l e c t s t h e v a r i a b i l i t y ance and p r o d u c t i o n on the open a r e a s .  i n f o r b abund-  Average p r o d u c t i o n  7h  F i g u r e 33.  The p r o d u c t i v i t y o f g r a s s on Premier Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  F o r e s t Canopy %  75  for  the t h r e e s i t e s was  15 gm/m ( l 4 7 2  Ib/AC.).  S i x t y - f i v e y e a r s a f t e r the onset o f f o r e s t r e g e n e r a t i o n , f o r b abundance dropped to 17$ o f i t s p r e v i o u s level.  Beyond e i g h t y y e a r s , f o r b p r o d u c t i o n i n c r e a s e s  i n c l i m a x stands  (over 2 5 0 y e a r s ) may  and  a c t u a l l y exceed the  p r o d u c t i o n a c h i e v e d on the open a r e a s . There i s l i t t l e change i n f o r b p r o d u c t i o n the f o r e s t canopy exceeds 5 0 $ cover p o i n t , p r o d u c t i v i t y decreases may  y i e l d abundance o f f o r b s .  trend i n F i g . 15, pine  (Fig. 34).  Beyond t h i s  a l t h o u g h an o c c a s i o n a l s i t e Tne  l a r g e d e v i a t i o n from the  a t 3 8 $ , r e p r e s e n t s t h e c l i m a x ponderosa  stand. c.  Dwarf Shrub P r o d u c t i v i t y  No m e a n i n g f u l  t r e n d s a r e d i s c e r n a b l e i n the dwarf  shrub d a t a f o r Premier Ridge.  Changes i n p r o d u c t i v i t y a r e  masked by changes i n s p e c i e s c o m p o s i t i o n and s o i l at  until  each s i t e .  moisture  The r e l a t i v e c o n t r i b u t i o n o f these p l a n t s  i s s m a l l , t h e i r p r o d u c t i o n i s shown i n F i g u r e 3 5 . d.  B e a r b e r r y Produc t i v i t y  The  e f f e c t of c h a r a c t e r i s t i c stand age on  the  annual p r o d u c t i v i t y o f b e a r b e r r y i s shown i n F i g u r e 3 6 . P r o d u c t i o n on open areas i s r e l a t i v e l y low, but r a p i d l y as f o r e s t r e g e n e r a t i o n commences.  increases  Beyond an  age  o f 50 y e a r s , most stands have become s u f f i c i e n t l y dense to cause some r e d u c t i o n i n b e a r b e r r y p r o d u c t i o n .  As  76  F i g u r e 34.  The p r o d u c t i v i t y o f f o r b s on P r e m i e r RIdg as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  70  9 —I—\—j—t—\ 0  20  40  *  \ \ u—T°T—i—i—i—i 60  80  100  C h a r a c t e r i s t i c Stand Age 70 C\J  i  ^  60  F o r e s t Canopy %  / 120  —r 280  77 n a t u r a l t h i n n i n g commences a t ages beyond 1 0 0 y e a r s , b e a r b e r r y p r o d u c t i o n i n c r e a s e s and i s f r e q u e n t l y a major component o f t h e u n d e r s t o r y v e g e t a t i o n o f t h e c l i m a x community. P r o d u c t i o n o f b e a r b e r r y i s low on t h e open s i t e s , r i s e s u n t i l canopy covers o f l e s s than 5 0 $ a r e reached  then  d e c l i n e s under canopies g r e a t e r than 5 0 $ ( P i g . 3 5 ) . e.  Bitterbrush Productivity  The open s i t e s a n n u a l l y produce v e r y l a r g e q u a n t i t i e s of b i t t e r b r u s h .  Some v a r i a b i l i t y among  open s i t e s r e s u l t s from d i f f e r e n c e s i n g r a z i n g  these  intensity.  The onset o f f o r e s t r e g e n e r a t i o n s e v e r e l y depresses brush p r o d u c t i o n .  Twenty-five  bitter-  y e a r s a f t e r r e g e n e r a t i o n had  commenced b i t t e r b r u s h p r o d u c t i o n was l e s s than 1/3 o f i t s former l e v e l .  F i f t y y e a r s l a t e r , p r o d u c t i o n was n e g l i g i b l e  and t h i s l e v e l w i l l be m a i n t a i n e d u n t i l t h e f o r e s t c l i m a x i s reached  I n w h i c h b i t t e r b r u s h u s u a l l y becomes more  abundant.  P r o d u c t i o n i n t h e c l i m a x f o r e s t compares f a v o u r -  a b l y w i t h a v e r a g e open s i t e s .  These t r e n d s a r e shown i n  Figure 37. The r e l a t i o n s h i p between b i t t e r b r u s h p r o d u c t i o n and f o r e s t canopy i s shown i n F i g u r e 3 7 -  P r o d u c t i o n , which  i s h i g h on t h e open s i t e s d e c l i n e s s t e a d i l y , except  f o r an  abrupt r e d u c t i o n a t 3 8 $ which r e p r e s e n t s t h e c l i m a x  stand  78  Figure 35.  The a n n u a l p r o d u c t i v i t y o f dwarf shrubs on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  F o r e s t Canopy %  79 36.  The a n n u a l p r o d u c t i v i t y o f b e a r b e r r y on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  F o r e s t Canopy %  80  o f p i n e and f i r .  Beyond a f o r e s t canopy o f 5 0 $ , b i t t e r -  b r u s h p r o d u c t i o n i s v e r y low, w h i l e a . f o r e s t canopy o f 2 6 $ i s s u f f i c i e n t t o lower p r o d u c t i o n t o 3 9 $ o f i t s former level.' f.  Soapoiallie  Productivity  The p r o d u c t i o n o f s o a p o i a l l i e v a r i e s l i t t l e s e r a i stage and  changes r e l a t i v e l y l i t t l e w i t h the one  with ex-  c e p t i o n t h a t on c e r t a i n s i t e s I t i s e x c e p t i o n a l l y p r o d u c t i v e and abundant j u s t b e f o r e and d u r i n g the stages forest regeneration.  S o a p o i a l l i e p r e f e r s moist s i t e s w i t h  s o i l moisture w e l l maintained and  of  through  the growing season,  i s not common i n pure stands o f ponderosa p i n e . F i g u r e 38  shows t h e p r o d u c t i v i t y of s o a p o i a l l i e under v a r i o u s canopies.  forest  S i n c e t h i s s p e c i e s f r e q u e n t l y grows under major  b r e a k s o r openings i n the canopy, an average canopy cover may  not be the most e f f e c t i v e way  preference.  to measureits  site  Canopy covers o f 2 0 $ to 4-0$ e x h i b i t the h i g h e s t  annual t w i g p r o d u c t i o n on an a r e a b a s i s . 2.  E s t e l l a Mountain a.  Grass  Productivity  The p r o d u c t i o n o f g r a s s on E s t e l l a Mountain f o l l o w e d a p a t t e r n s i . m i l a r to Premier Ridge, but was than t h a t o f t h e lower a r e a .  The  somewhat h i g h e r  e f f e c t of c h a r a c t e r i s t i c  stand age on g r a s s p r o d u c t i o n i s shown In F i g u r e 3 9 .  Pro-  •  8i  ;..  The a n n u a l p r o d u c t i v i t y o f b i t t e r b r u s h ( t w i g s and t h e i r l e a v e s o n l y ) on P r e m i e r Ridge as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  I i I I I I l 20  40  60  Characteristic  1—7 10  I I I I 80  Stand  100  120  Age  20  F o r e s t Canopy % t e x t f o r e x p l a n a t i o n of t h i s p o i n t  I /  280  82  Figure 38.  The a n n u a l p r o d u c t i v i t y o f s o a p o i a l l i e ( t w i g s l e a v e s ) as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d and f o r e s t canopy. P r e m i e r Ridge s i t e s .  F o r e s t Canopy %  and age  83 d u c t i o n i s h i g h on open s i t e s , 54 gm/m  2  (529 l h / a c . ) and  d e c l i n e s r a p i d l y as f o r e s t r e g e n e r a t i o n commences.  After  35 y e a r s g r a s s p r o d u c t i o n i s 28$ o f t h a t a c h i e v e d on open areas.  P r o d u c t i o n i n c r e a s e s as stands mature and  62$ o f the open area, p r o d u c t i o n i n 125  reaches  years.  Grass p r o d u c t i o n d e c l i n e s s t e a d i l y w i t h i n c r e a s i n g f o r e s t canopy. recorded  The low l e v e l s o f p r o d u c t i o n which were  f o r Premier Ridge under dense f o r e s t c a n o p i e s do  not seem t o o c c u r on E s t e l l a Mountain ( F i g . 39). b.  Forb P r o d u c t i v i t y  The  f o r b p r o d u c t i o n o f the open a r e a s on E s t e l l a  Mountain i s r e l a t i v e l y h i g h , b e i n g composed o f fewer s p e c i e s than i s c h a r a c t e r i s t i c o f the lower, more h e a v i l y grazed ranges.  Mean y i e l d s on open s i t e s was 18 gm/m  They d e c l i n e s t e a d i l y as f o r e s t canopy and stand age  increase.  (l60  lb/ac.).  characteristic  T h i r t y - t h r e e y e a r s a f t e r the onset o f  f o r e s t r e g e n e r a t i o n t h e f o r b y i e l d i s reduced b y 50$.  The  f o r e s t canopy a s s o c i a t e d w i t h such. a. d e c l i n e i s about  70$.  Forb p r o d u c t i o n i s shown I n F i g u r e 40. c.  Dwarf Shrub P r o d u c t i v i t y  The  r e l a t i o n s h i p between c h a r a c t e r i s t i c s t a n d age  and dwarf shriib p r o d u c t i v i t y i s shown i n F i g u r e 41. v a r y from 3 t o 12 gm/m  2  (27 t o 167  Yields  l b / a c . ) on theopen s i t e s  and remain a t t h e s e l e v e l s f o r the f i r s t 30 t o 40 y e a r s o f tree regeneration.  Y i e l d s i n o l d e r stands a r e v e r y  low,  84  Figure 39.  The p r o d u c t i v i t y o f g r a s s e s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  F o r e s t Canopy %  85 2 gm/m  (17 l b / a c ) .  There was no d i s c e r n a b l e r e l a t i o n s h i p  between dwarf shrub p r o d u c t i o n and f o r e s t canopy, as shown in Figure 4 l . d.  Bearberry  Productivity  B e a r b e r r y was v e r y abundant on one s i t e on E s t e l l a At a l l o t h e r s i t e s I t y i e l d e d  Mountain. (44.5  lb/ac).  l e s s than 5 gm/m  2  There*are n o t s u f f i c i e n t o b s e r v a t i o n s t o  a s c e r t a i n whether t h i s i s a common phenomenon. appears t o be depressed  Productivity  i n open a r e a s and under v e r y dense  f o r e s t c a n o p i e s , b e i n g somewhat h i g h e r a t i n t e r m e d i a t e canop i e s , as shown i n F i g u r e 4 2 . e.  Bitterbrush  Bitterbrush at the e l e v a t i o n s f.  Productivity  does n o t o c c u r on E s t e l l a Mountain  a t which t h e p l o t s were  Soa^polallie  established.  Productivity  The p r o d u c t i v i t y o f s o a p o i a l l i e i s shown i n F i g u r e 43.  C o m p a r a t i v e l y l i t t l e y i e l d i s a c h i e v e d on the open,  r e c e n t l y burned a r e a .  P r o d u c t i o n r i s e s s h a r p l y as the f o r e s t  b e i n g s t o r e g e n e r a t e and u s u a l l y remains h i g h under dense f o r e s t canopies. conditions  S o a p o i a l l i e seems t o s u r v i v e under t h e s e  by growing near major b r e a k s i n t h e f o r e s t canopy.  D.  O v e r s t o r y Community Composition  1.  Premier  Ridge  The seven f o r e s t e d  s i t e s on Premier Ridge range i n  86  F i g u r e 40.  The p r o d u c t i v i t y o f f o r b s on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t ca.nopy.  F o r e s t Canopy %  87 F i g u r e 41.  12 OJ  g W  C  o  •H  o  T) O U  PH  10  The p r o d u c t i v i t y o f dwarf shrubs on E s t e l l a Mountain as I n f l u e n c e d by c h a r a c t e r i s t i c stand age and f o r e s t canopy.  1  8 6 4 2 T  0  J—"T  1.0  20  S  30  1  40  f—\  50  60  F o r e s t Canopy $  T—1  80  90  S  100  1  120  88 age from 22 t o 280 y e a r s , spanning a f o r e s t canopy cover  26$ t o 78$.  The most dense s t a n d ,  3,4-59 stems  from'  per a c r e , a l s o  had the h i g h e s t f o r e s t canopy, 78$, and i s r e p r e s e n t a t i v e of the l o d g e p o l e p i n e f i r e s e r e s o f the s o u t h e r n Rocky Mountain  Trench.  The c l i m a x ponderosa  p i n e s i t e b y compari-  son had o n l y 74 stems p e r a c r e w i t h a. f o r e s t canopy o f In g e n e r a l , ponderosa  38$.  p i n e stands occupy more  x e r i c s i t e s than the Douglas f i r and tend t o have fewer stems per a c r e and more open c a n o p i e s .  In a d d i t i o n , the f i r  s i t e s tend t o be c l u s t e r e d near the n o r t h e r n end o f the r i d g e whi.ch i s m e s i c , l a r g e l y due t o the m i c r o c l i m a t i c e f f e c t s o f a c o o l e r exposure.  The o n l y western l a r c h o c c u r s  i n a s s o c i a t i o n w i t h f i r . s t a n d s a t the n o r t h end o f t h e ridge. 2.  E s t e l l a . Mountain The t h r e e f o r e s t s i t e s on E s t e l l a Mountain  r e p r e s e n t a t i v e o f f o r e s t s o f warmer exposure, the southwestern a s p e c t s from tion.  4,000  to  7,000  are  particularly feet i n eleva-  The c h a r a c t e r i s t i c stand age v a r i e s from 25 t o 125  y e a r s w i t h a f o r e s t canopy range o f 35$ t o 72$. The E s t e l l a Mountain  f o r e s t s do not tend t o t h i n t h e i r canopy  n a t u r a l l y as t h e y mature, but remain r e l a t i v e l y dense, u n l i k e those o f Premier Ridge.  Consequently o n l y the youngest  forest  ( l e s s than 25 y e a r s o l d ) e x h i b i t c o m p a r a t i v e l y low f o r e s t  89  F i g u r e 42.  , s OJ  6 ^—'  C  o  120 100 80  •H -p O  6o  •a  4o  o  u P-,  The a n n u a l p r o d u c t i v i t y o f b e a r b e r r y on E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age and f o r e s t canopy.  20  1 -.1  o  \  20  \ s f  4o  s i—I 6o  Characteristic  I 1  8o  Stand  I IOO  m  120  Age  120 OJ 6  100 80  o  •H -p O • 3 •a  o  60 4o 20 e  e  1—1—I 8o  F o r e s t Canopy %  90  ioo  90  F i g u r e 43.  The a n n u a l p r o d u c t i v i t y o f s o o p o l a l l i e ( t w i g s and l e a v e s ) as i n f l u e n c e d by c h a r a c t e r i s t i c stand age and f o r e s t canopy. E s t e l l a s i t e s .  Table V I I  S i t e s t a t i s t i c s f o r t r e e s Premier Ridge 1 9 6 9 .  Young Douglas Fir  Mid. Douglas Fir  Mature Douglas Fir  Young Ponderosa Pine  C h a r a c t e r i s t i c Stand Age  22  55  95  80  100  280  65  F o r e s t Ca;nopy %  26  56  73  49  49  38  78  No. t r e e s p e r a c r e  1930  605  331  958  Mid. Ponderosa Pine  261  No, t r e e s i n m a c r o p l o t  443  139  76  220  60  No. Douglas f i r  438*  135*  76*  142  13  3  No. Ponderosa p i n e No. Lodgepole p i n e  3  No. L a r c h  2  * denotes c u r r e n t dominants.  67 1  1  47*  Climax Ponderosa Pine  Lodgepole Pine  47  3459  17  794  4  133  .13*  328 333*  --o  92  canopy c o v e r l e s s than 3 5 $ .  S e l e c t i v e l o g g i n g has  the c a n o p i e s o f the r e g e n e r a t i n g f i r s i t e and the site.  The  thinned larch  e f f e c t of t h i s t h i n n i n g i s s i m i l a r to the  n a t u r a l t h i n n i n g seen on Premier R i d g e , but q u i t e d i f f e r e n t from t h e e f f e c t s o f c l e a r - c u t l o g g i n g .  Selective logging  on E s t e l l a has t r i g g e r e d a c t i v e r e g e n e r a t i o n o f Douglas f i r a t b o t h the a f o r e m e n t i o n e d The  sites.  l o d g e p o l e p i n e s i t e r e s u l t s from a hot  which burned up t h e w e s t e r n exposure i n 1931.  The  fire  of E s t e l l a Mountain  l o d g e p o l e s i t e i s on an a r e a p r e v i o u s l y  f o r e s t e d by w h i t e - b a r k e d p i n e .  T h i s s t a n d c o n s t i t u t e s the  densest f o r e s t s i t e on the mountain, w i t h 1 , 6 3 4 stems p e r a c r e , the l o w e s t b e i n g the r e g e n e r a t i n g f i r s i t e w i t h 5 5 3 stems per a c r e .  The f o r e s t stands on E s t e l l a tend t o be  composed l a r g e l y o f a s i n g l e s p e c i e s , a t l e a s t  initially.  T h i s i s e s p e c i a l l y t r u e f o r t h e l o d g e p o l e a c r e s which  follow  fires. E.  S i t e H i s t o r y and the Path o f S u c c e s s i o n on Premier In p r i s t i n e times the west and southwest  Ridge  slopes  o f Premier Ridge were l a r g e l y covered w i t h mature, c l i m a x stands o f ponderosa p i n e and Douglas f i r .  Moist northern  and n o r t h e a s t e r n s l o p e s were e s t a b l i s h e d t o Douglas f i r and  l a r c h , f r e q u e n t l y i n dense s t a n d s . As a f o r e m e n t i o n e d ,  l o g g i n g began on Premier  Ridge  93  Table V I I I  S i t e s t a t i s t i c s f o r t r e e s E s t e l l a Mountain 1 9 6 9 .  Regen. Douglas Elevation Characteristic  4500  Stand Age  Fir  W. L a r c h 4500  Lodgepole Pine 6000  25  125  35  35  72  71  No. t r e e s p e r a c r e  553  1255  1634  No. t r e e s i n s i t e  127  288  No. Douglas F i r  121*  185  No. Lodgepole P i n e  3  19  No. L a r c h  3  F o r e s t Canopy f>  * denotes c u r r e n t dominants.  1  84  375  375*  94  about 1910 and was  w e l l underway by 1 9 2 0 .  The mature  f o r e s t s o f ponderosa. p i n e and Douglas f i r were removed  from  a l l but a few r e l a t i v e l y i s o l a t e d o r i n a c c e s s i b l e a r e a s o f the r i d g e .  V i r t u a l l y a l l o f the l a r g e Douglas f i r was  at t h i s t i m e .  cut  Table IX shows the number o f stumps by s p e c i e s  p r e s e n t a t the s i t e s  selected for intensive  examination.•  Table X t r a c e s the h i s t o r y o f each s i t e as f a r back as possible. (ca.  In most cases t h e n a t u r e o f t h e mature f o r e s t  2 0 0 y e a r s o l d ) can be determined  from the stumps which  have remained s i n c e the l o g g i n g o f the e a r l y 1 9 0 0 ' s . it  Thus  i s p o s s i b l e t o determine g e n e r a l l y the n a t u r e o f a. f o r e s t  c o v e r which began t o d e v e l o p about 1700  A.D.  Logging o f t h e mature, c l i m a x f o r e s t r e s u l t e d i n the regrowth o f a s t a n d o f s i m i l a r s p e c i e s c o m p o s i t i o n i n most cases..  Possibly a slight increase i n p r e c i p i t a t i o n  over the l a s t few decades has r e s u l t e d i n an i n c r e a s e In the numbers o f young Douglas f i r i n stands which were mixed w i t h p i n e and f i r .  In some c a s e s , r e c e n t l y c u t ponderosa p i n e  stands which were not burned have become e s t a b l i s h e d t o Douglas f i r . The water t a b l e i n t h e a r e a may shown by the r i s i n g water  a l s o r i s e as  l e v e l o f A l k a l i Lake.  S i n c e the  c l i m a x montane f o r e s t c o n s i s t s o f an i n t e r g r a d e o f ponderosa p i n e and D o u g l a s . f i r , o c c u r r i n g i n mixed s t a n d s , o r o c c a s i o n a l l y i n pure stands of e i t h e r s p e c i e s , an i n c r e a s e i n m o i s t u r e might s h i f t t h e s p e c i e s , e s t a b l i s h m e n t p a t t e r n s i n f a v o u r o f  95 Douglas f i r .  Ponderosa p i n e i s v e r y c l o s e t o i t s n o r t h e r n  l i m i t i n the Southern Rocky Mountain  Trench.  F i r e i n t h e s e stands i s f o l l o w e d "by the e s t a b l i s h ment o f p i n e i n most c a s e s . to  A more s e v e r e f i r e i s needed  e l i m i n a t e the ponderosa p i n e due to i t s l o o s e , f i r e  r e s i s t a n t b a r k , however a s u f f i c i e n t l y hot ground i n the c l i m a x p i n e f o r e s t may lodgepole pine.  fire  t r i g g e r an u n d e r s t o r y o f  Dense s t a n d s o f l o d g e p o l e p i n e f r e q u e n t l y  c o n t a i n young ponderosa p i n e and Douglas f i r t r e e s .  Appar-  e n t l y , i t t a k e s about 120 y e a r s on most s i t e s , w i t h o u t for  fire,  the lodgepole t o t h i n s u f f i c i e n t l y t o permit f i r or  ponderosa p i n e t o become dominant. up t o l 8 0 y e a r s o l d may  Lodgepole v e t e r n a s  be found i n r e g e n e r a t i n g ponderosa  p i n e and Douglas f i r s t a n d s , i n d i c a t i n g t h e e a r l i e r p r e s s u r e of  f i r e a t the  site.  S e r a i g r a s s l a n d s may  form a d l s c l i m a x f o r s e v e r a l  decades on d r i e r s l o p e s f o l l o w i n g the removal o f t h e mature forest.  The open t e r r a c e a r e a o f Premier Ridge f o l l o w e d  this pattern.  However, young Douglas f i r s have become e s t a -  b l i s h e d i n m o i s t g u l l i e s and i n time w i l l r e i n v a d e t h e a r e a f o r m e r l y o c c u p i e d by t h e f o r e s t . F.  S i t e H i s t o r y and t h e Paths of S u c c e s s i o n on Mountain  Estella  Logging has e x e r t e d o n l y a minor i n f l u e n c e on s o u t h and southwestern  s l o p e s of E s t e l l a Mountain.  the  Cutting  Table IX  S t a t i s t i c s f o r stumps, Premier Ridge, Relict Agropyron  No. stumps per acre No. stumps In macroplot No. D. F i r stumps  1969. Ponderosa Pine Young Middle Climax  Poa-stlpa  13  139  9  22  9  9  . 9  0  3  32  2  5  2  2  2  0  32/14.7  2/N.A.  *3/l4.7  Young  Douglas F i r Middle Mature  Purshla  4/15.2 2/18.5  2/N.A. 2/18.2  No. P. Pine stumps  Lodgepole Pine  2/24.3  1/13.0  No. Larch stumps No. Lodgepole Pine stumps  ON  *  Note:  3/14.7  numerator = no. stumps denominator = average diameter of stump 1" o f f ground In Inches.  Table X  F o r e s t cover o f Premier Ridge s i t e s ,  S i t e Name  Previous  R e l i c t bluebunchwheatgrass  Open m a t u r e fir  Bitterbrush  Dense mature Dougla.s fir  Clear  cut & burned  Shrub & s e r a i grassland  Bluegrass-needlegrass  Open c l i m a x fir  Clear  cut & burned  Shrub & s e r a i grassland  Young D o u g l a s f i r  Semi-open c l i m a x Douglas f i r  Selective  Mid. Douglas f i r  Open c l i m a x fir  Selective logging 1920 to present  Mature  Probably fir  Yg. Mid.  Douglas f i r  Ponderosa Ponderosa  Pine Pine  Climax Ponderosa Lodgepole  Pine  Pine  Forest  p a s t and p r e s e n t .  Douglas  Douglas  Douglas  Clear  Bunchgrass  1920  1920  logging  1920 & 1965  N.A.  Ponderosa  Clear cut  Cover sere  None Ponderosa  Burned  1931  Regen. D o u g l a s f i r & veterans Regen. D o u g l a s ( a l l ages) Dense M a t u r e fir  1920  Increase ppt. (?)  A.  Open c l i m a x Pine  c u t & burned  mature  Serai grassland  N.  Present  1920  dense  Open c l i m a x Pine  Nature o f D i s t u r b a n c e  f i r  ^  Douglas  Yg. P o n d e r o s a P i n e & Douglas f i r regen. Mature stand Pine .  Ponderosa  Open c l i m a x montane Dense L o d g e p o l e P i n e o l d Ponderosa Pine v e t e r a n s w i t h some Douglas f i r regen.  forest &  TABLE XI  THE PATHS OF SUCCESSION ON PREMIER RIDGE  SELECTIVE LOGGING  MAINTAINS YOUNG TO MATURE STAND OF DOUGLAS FIR AND PONDEROSA PINE WITH SOME OLD VETERANS 100-200 YEAR CYCLE DEPENDING UPON ASPECT  Climax  Lodgepole  pine forest  Montane  si  Forest  Open brush & serai  grassland  DISCLIMAX MAINTAINED BY SITE MOISTURE AND GRAZING PRESSURES  Table X I I  S t a t i s t i c s f o r stumps, E s t e l l a Mountain, . 1969 Serai Bluebunch Wheatgrass  Serai Fescue  No. stumps p e r a c r e  44  88  No.' stumps p e r s i t e  10  20  •  Regen. Douglas F i r  Larch  57  88  26  13  20  6  Lodgepole  No. Douglas f i r stumps No. WB p i n e stumps  10/6.5  18/14.8  13/12.6  3/23.3  7/12.6  3/18.8  13/12.1  No. Lodgepole p i n e stumps No. L a r c h stumps  Note:  1/16.1  numerator = No. stumps denominator = average d i a m e t e r i n i n c h e s 1 f o o t from ground  level  Table X I I I  F o r e s t cover o f E s t e l l a . M o u n t a i n , past and p r e s e n t .  S i t e Name  Previous Forest  Nature of D i s t u r b a n c e  Present  Regen. Douglas f i r  Semi-open mature Douglas f i r  Selective logging  Semi-open mature Douglas f i r  Dense L a r c h  Selective logging  L a r c h w i t h Douglas . fir understory  Lodgepole P i n e  Mature WB p i n e stand  Burned  1931  Dense Lodgepole Pine forest  S e r a i fescue  Mature WB p i n e forest  Burned 1 9 3 1  Serai grassland with WB p i n e s e e d l i n g s  S e r a i bluebunch wheatgrass  Mature WB p i n e forest  Burned 1 9 3 1  Serai grassland with WB p i n e s e e d l i n g s  Larch  site.  1952  1952  Cover  101  has been c o n c e n t r a t e d on t h e more p r o d u c t i v e n o r t h and n o r t h western  s l o p e s which a r e dominated by Englemann s p r u c e .  south and southwestern  s l o p e s a r e e s t a b l i s h e d t o Douglas f i r  w i t h some s e r a i stands o f w e s t e r n a s p e c t s above  5*000  f e e t was  of white-barked pine. was  The  larch.  The a r e a on  these  p r e v i o u s l y covered by a f o r e s t  The r e g e n e r a t i n g Douglas f i r s i t e  s e l e c t i v e l y c u t about 1952 and i s c u r r e n t l y r e g e n e r a t i n g  t o Douglas f i r . zone and was  The  l a r c h s i t e i s a l s o i n the Douglas f i r  s e l e c t i v e l y cut about 1 9 5 2 .  f a v o u r e d an x m d e r s t o r y  o f Douglas f i r .  T h i s t h i n n i n g has These t r e e s w i l l ,  d o u b t l e s s i n t i m e , e l i m i n a t e o r reduce the now larch.  dominant  S c a t t e r e d o l d ( l 8 0 y e a r s ) l o d g e p o l e p i n e s a t both  o f t h e s e s u t e s suggest t h a t t h e y were p r o b a b l y burned over 200 y e a r s  ago. The r e m a i n i n g t h r e e s i t e s on E s t e l l a Mountain were  e s t a b l i s h e d on the burn o f 1931 which c o m p l e t e l y d e s t r o y e d the w h i t e - b a r k e d p i n e f o r e s t .  The  lodgepole pine s i t e i s  r e p r e s e n t a t i v e o f the a r e a s which were r e f o r e s t e d s h o r t l y a f t e r the burn.  Stumps o f any f o r e s t which might have  e x i s t e d p r i o r t o t h e w h i t e - b a r k e d p i n e f o r e s t c o u l d not found.  be  N e i t h e r w h i t e - b a r k e d p i n e s e e d l i n g s nor the s e e d l i n g s  o f any o t h e r c o n i f e r c o u l d be found under the dense stands of lodgepole p i n e .  These s e e d l i n g s a r e , however, now  be-  coming e v i d e n t i n open a r e a s which were burned but f o r some  TABLE XIV  i  THE PATH OF SUCCESSION ON ESTELLA MOUNTAIN (SW & S aspect)  DOUGLAS FIR ZONE  Larch  o  Lodgepole pine forest  serai  grassland  DISCLIMAX ACCORDING TO SITE PPT (ASPECT) 100 YEAR MAXIMUM CYCLE  11 WHITE-BARKED PINE ZONE  Mature White-bark pine Forest  Lodgepole pine forest  Serai  grassland  80 YEAR MAY CYCLE  DISCLIMAX DEPENDENT UPON SITE AND PPT. AND ASPECT  10.4  reason ( o f t e n a s p e c t ) have f a i l e d t o r e g e n e r a t e t o l o d g e pole pine. G.  The P r o d u c t i v i t y o f t h e F o r e s t  1.  Premier  Ridge  No attempt was made t o determine t h e t o t a l or n e t p r o d u c t i v i t y o f t h e f o r e s t .  annual  The methods r e q u i r e d t o  measure n e e d l e f a l l , "branch growth and r o o t growth were beyond t h e scope o f t h i s i n v e s t i g a t i o n .  For comparative  e x a m i n a t i o n o f t h e s i t e s , t h e t o t a l volume o f t i m b e r was. determined  i n each m a c r o p l o t and s u b s e q u e n t l y c o n v e r t e d t o  acre u n i t s .  The average a n n u a l increment was a l s o r e c o r d e d .  These d a t a g i v e some i n d i c a t i o n o f t h e f o r e s t biomass w h i c h i s b e i n g m a i n t a i n e d a t each s i t e and t h e r a t e a t w h i c h i t i s increasing. Table XV l i s t s t h e f o r e s t p r o d u c t i v i t y d a t a f o r Premier R i d g e .  The t o t a l volume o f t i m b e r i n c r e a s e s w i t h  age, a p p a r e n t l y r e a c h i n g a peak i n t h e mature Douglas f i r s i t e which had  3,593  c u b i c f e e t o f stem wood.  T h i s s i t e was  b e g i n n i n g t o t h i n i t s e l f and t h e c e n t r e s o f many o f t h e l a r g e r t r e e s showed s i g n s o f r o t , r e d u c i n g t h e i r value.  The ponderosa  p i n e s i t e s c o n t a i n much l e s s t i m b e r  volume than t h e c o r r e s p o n d i n g Douglas f i r s i t e s . ponderosa  commercial  The c l i m a x  p i n e s i t e had a lower t i m b e r volume and a much  lower a n n u a l increment pine s i t e s .  (5.7 cu f t / a c ) than any o f t h e o t h e r  In s p i t e of x e r i c nature of the s i t e , lodgepole  t o wood p r o d u c t i o n , Premier R i d g e s i t e s .  No. stems p e r a c r e  1  C  •r-i PH  .P-i xi •H  1 Climax P.  c  CD  1  u  CD  c CD  Yg. P. Pj  i  Mid D. Fj  Yg. D. Fj  •u  Mat. D. Fir  CD  ' Lodgepole P"  Statistics relating  1  T a b l e XV  1930  605  331  958  261  s  74  3459  C h a r a c t e r i s t i c sta.nd age  22  55  95  80  100  280  65  F o r e s t canopy %  26  56  73  • 49  49  38  78  DBH a r e a p e r a c r e  4oo  91  161  130  109  74  701  Mean DBH a r e a  .21  .15  .49  .15  .42  1.0  .20  T o t a l wood volume f t 3  1115  892  3593  919  1729  1573  l4li  Annual increment* f t 3  50.5  16.5  37.5  11.3  16.6  5.7  21.3  a n n u a l increment  =  t o t a l wood volume ( f t 3 ) c h a r a c t e r i s t i c s t a n d age ( y r . )  .  io6  p i n e stands showed a good a n n u a l increment 2.  (21.3 cu f t / a c ) .  E s t e l l a Mountain The p r o d u c t i v i t y d a t a f o r t h e t i m b e r o f t h e E s t e l l a  Mountain s i t e s i s r e c o r d e d i n T a b l e X V I .  The number o f stems  per a c r e o f t h e E s t e l l a s i t e i s s i m i l a r t o t h o s e s i t e s o f c o r r e s p o n d i n g age on Premier R i d g e .  Natural thinning of  mature stands does n o t o c c u r and t h e s e o l d e r s t a n d s tend t o be more dense than t h e i r lower e l e v a t i o n c o u n t e r p a r t s .  The  volume o f t i m b e r on t h e young stands on E s t e l l a and P r e m i e r are  comparable.  The r e g e n e r a t i n g f i r s t a n d on E s t e l l a had  a: volume o f 9 6 7 c u b i c f e e t o f wood w h i l e t h e young Douglas f i r s t a n d on Premier had a wood volume o f 1 , 1 1 5 c u b i c f e e t . At m a t u r i t y t h e D o u g l a s f i r and l a r c h f o r e s t s o f E s t e l l a -  y i e l d volumes o f t i m b e r h i g h e r than t h e mature f i r stands on P r e m i e r , a l t h o u g h the "mature Douglas f i r " s i t e on t h e n o r t h e a s t s l o p e o f Premier produced a s u b s t a n t i a l volume o f timber  (3,4-93  f t . ) due t o i t s m o i s t a s p e c t .  The E s t e l l a f o r e s t grows more q u i c k l y than those of Premier R i d g e .  At an age o f 35 y e a r s t h e y have s u r p a s s e d  the t o t a l wood y i e l d s o f t h e lower e l e v a t i o n s .  The a n n u a l  increment o f t h e l o d g e p o l e p i n e s t a n d on E s t e l l a was 6 7 . 5 f t / y e a r , ' t h e h i g h e s t measured d u r i n g t h i s s t u d y . D i f f e r e n c e s i n s t o c k i n g d e n s i t y and s p e c i e s compos i t i o n o f t h e f o r e s t s made f u r t h e r comparison somewhat d i f f i cult.  107  Table XVI  Statistics relating Mountain s i t e s .  t o wood p r o d u c t i o n , E s t e l l a  Regen. D. F i r No. stems p e r a c r e C h a r a c t e r i s t i c stand age F o r e s t canopy %  •  Larch  573  1633  25  125  Lodgepole P i n e 1254 35  35  72  71  126  266  170  .24  .21  .11  T o t a l DBH a r e a per acre Mean DBH a r e a T o t a l wood volume per acre (ft3) Annual increment* per a c r e  *  a n n u a l increment  967  _  =  38.3  3332  26.6  2365  67.5  t o t a l wood volume ( f t 3 ) c h a r a c t e r i s t i c s t a n d age ( y r . )  108.  H.  Aggregate U n d e r s t o r y  I.  Premier Ridge The  Productivity  t o t a l annual understory p r o d u c t i v i t y i s  p r e s e n t e d i n two forms; one,  considering  w i t h c h a r a c t e r i s t i c s t a n d age, r e l a t i o n s h i p with The  and two,  i t s relationship considering  its  f o r e s t canopy.  e f f e c t o f c h a r a c t e r i s t i c s t a n d age  u n d e r s t o r y p r o d u c t i v i t y i s shown i n F i g u r e 4 5 ,  on the including,  f o r c o m p a r a t i v e p u r p o s e s , the p r o d u c t i o n o f the n a t u r a l • grassland.  The p r o d u c t i v i t y o f the t h r e e open s e r a i s i t e s  averages 7 1 . 7  gm/m  2  (638 l b / a c ) .  component o f t h i s y i e l d .  gm/m  2  (1,334  largest  The p o t e n t i a l p r o d u c t i v i t y o f t h e s e  areas (under a b e t t e r g r a z i n g 150  Grasses form the  regime) i s p r o b a b l y about  lb/ac).  T o t a l p r o d u c t i v i t y i n c r e a s e s s l i g h t l y as f o r e s t r e g e n e r a t i o n commenced.  T h i s r i s e was l a r g e L y  c r e a s e s i n the b e a r b e r r y and  due  soapoiallie yields.  t o InThe g r a s s  component and the b i t t e r b r u s h components, w h i c h are used b y g r a z e r s ,  decreased s h a r p l y  in yield.  heavily  The stands  from 5 0 t o 100 y e a r s o f age show depressed t o t a l  productivity  r e a c h i n g o n l y 5 6 $ of the a g g r e g a t e p r o d u c t i o n o f the open s e r a i communities. production  A l l components showed a d e c r e a s e i n  and i n extreme cases a component o r s p e c i e s may  a c t u a l l y disappear e n t i r e l y .  Forbs may-be abundant on m o i s t  109  sites.  As t h e f o r e s t matures and approaches the c l i m a x  s t a t e , the t o t a l p r o d u c t i v i t y i n c r e a s e s l a r g e l y due natural thinning.  The h e l i o p h y t e s reappear  to  and make  s i g n i f i c a n t c o n t r i b u t i o n s t o i n c r e a s e the y i e l d .  The  f o r b s , b e a r b e r r y and b i t t e r b r u s h f r a c t i o n s a l l i n c r e a s e d markedly i n the c l i m a x f o r e s t .  However, g r a s s p r o d u c t i o n  i n the c l i m a x stand remains low, a c h i e v i n g o n l y 5 0 $ o f t h e y i e l d a t t a i n e d on the u n f o r e s t e d s i t e s .  F i g u r e 44  shows the r e l a t i o n s h i p between u n d e r s t o r y p r o d u c t i v i t y and f o r e s t canopy. aggregate  Under a canopy cover o f 2 o $ the  p r o d u c t i v i t y i n c r e a s e s s l i g h t l y , due t o i n c r e a s e s  i n y i e l d by b e a r b e r r y and  soapoiallie.  F o r e s t canopy v a l u e s g r e a t e r than 5 0 $ a r e a s s o c i a t e d with, a reduced  p r o d i r t i v i t y o f the u n d e r s t o r y .  P r o d u c t i o n under the h i g h e r f o r e s t canopy v a l u e s and 7 8 $ ) was communities.  reduced  (72$  t o 6 0 $ o f t h a t o f the n o n f o r e s t e d  The g r a s s component d e c l i n e d s t e a d i l y as  the f o r e s t canopy i n c r e a s e d .  The  100$ Increase i n pro-  d u c t i v i t y o f the open f o r e s t stands  ( 2 6 $ and 3 8 $ canopy)  i s due to an i n c r e a s e i n b e a r b e r r y . The a n n u a l increment  o f the t i m b e r . a t each s i t e  has not been i n c l u d e d i n F i g u r e 4 4 .  Apparently bearing  l i t t l e r e l a t i o n s h i p t o u n d e r s t o r y y i e l d s , the increment  of  timber d e c l i n e s r a t h e r s t e a d i l y , b e i n g h i g h e s t i n the young-  CT  I  ro  VJ1  o  H  O o  1 *|natural  o  i  TO  grassland  4  CD  H* (-3 3 p~ CD I—  1  £ PJ  fij CT  o  4  CD CD CLCT P  cr c t << CD  ro o  M}  03  o b  CD £  W P  *1  o  •i  (D  ct  H  o  5  co  o  O  ct  •  o cu  o  CL CD  4  r  «<5  < 4  3 P CP.  o  o  Ct  O > S  0<<  4=r O  Ul  CQ  O  a  C  o  ct 4 H*  zarzi  <!  O f O Ct 3  IM  OA  o  P cn  CQ CD CQ o  o cr co 4  oo Lx) 4  Ct Ct  CD  c  4  c  cr  CO  si  co  02  O  o o  P  H I— h" CD  1  tri  CD pj 4  0)  4  CD 3 i-d  ct 4  CO CD „ B P p. 4 CD CD 4 O ft) 3* H-  P D-, 4 CT P CD  O Ct CD CD CO  4 N CD  co o  a  on  Figure 4 5 Figure 4 5  The a g g r e g a t e a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f P r e m i e r R i d g e a s i n f l u e n c e d b y c h a r a c t e r i s t i c s t a n d age Only major components a r e shown. The a g g r e g a t e a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f P r e m i e r R i d g e as Bitterbrush i n f l u e n c e d by c h a r a c t e r i s t i c stand age. Only major components a r c Dwarf Shrubs shown. ^  Soopolallie Forbs Grass Bearberry  150  100  gm/m"  5 0  n l l l i I 20  40  30  Characteristic  Stand  Age  I 50  60  /  •-3  O ct  P  w  CQ  cd  ro.  ct ct  CD  P cr CD  • 'ri. rr CD  4  QJ  H-  P  CD  •D  cr  CA  H-  P  o  cn  13-  cr  •-3  Q  P  P  cr  i—i CD  cn  J>d <j  rr  H H  cr  .i-3 tr  ro  CO  i  o  i  i  H  o  —«3  o  Skookumchuck  Prairie  P 09  >s  CD 09,  00  o^  0>  oo  CO  OO  Ul  R e l i c t Agropyron  oo  H UJ  O  ct  ro P  4="  4="  OO CO  4^ -<1  4=-  ro  o  oo  H  P  Purshia  P  Ul 03 4=r  o  ui  o  oo  Poa-stipa  ro co ct  co  O  <<  Ul I—  1  t-  1  ui  ro ro  00 ro  o->  ui  M  o  ON  ui  CT\  H  oo  ui  4=-  vo  H  Yg. D. P i r  <n 4  o  aMid D. F i r  d o  ct  H» <J HCt  oo  oo  H  H  1  Ul  i~3  i-3  ro  H  ^o  o\  1-3  ro  ro  4=-  4=-  vo  ro o  H  Lodgepole  Yg.. P. P i n e  ^ O  ro 3  ro  ro  ro  Ul  ro  o Ul  ro CT\  4^OO  vo  Mat. D. F i r  oo  oq  ro  M O^  O  H  Ul  H>  o  vo  oo  o  0^ ro  OO  i—  1  4=-  4=-  O  H  Mid P. P i n e  00 ro  ui  SIT  Climax  CD  1 : L  3  est s t a n d and l o w e s t i n t h e o l d e s t . t r e n d i s t h e mature Douglas  One d e v i a t i o n from t h i s  f i r (age 95 y e a r s ) which i s  l o c a t e d on the m o i s t n o r t h e a s t s l o p e and would  consequently  be expected t o grow more r a p i d l y . 2.  E s t e l l a Mountain The net a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a  Mountain f o l l o w s a p a t t e r n s i m i l a r t o t h a t found on Premier Ridge.  Open a r e a s g e n e r a l l y produce h i g h y i e l d s , o f h e r b -  aceous s p e c i e s , w h i l e the f o r e s t s i t e y i e l d s tend t o be reduced p r i n c i p a l l y i n t h e g r a s s component. y i e l d o f herbaceous  The i n c r e a s e d  s p e c i e s n o t e d i n young r e g e n e r a t i n g  stands on P r e m i e r Ridge, was r e p e a t e d on E s t e l l a .  However,  a l l o f t h e i n c r e a s e d p r o d u c t i v i t y a t t h e 25 y e a r o l d s i t e r e s u l t e d from b e a r b e r r y .  The dwarf shrub component  was  s h a r p l y reduced a t o l d s i t e s w i t h h i g h f o r e s t canopy values.  The e f f e c t o f t h e f o r e s t canopy on t h e u n d e r s t o r y  p r o d u c t i v i t y i s shown i n F i g u r e 4 7 .  The n e t u n d e r s t o r y  p r o d u c t i v i t y d e c l i n e s as f o r e s t r e g e n e r a t i o n commences. The i n c r e a s e i n y i e l d a t 3 5 $ c o v e r i s e n t i r e l y due t o b e a r berry.  The dense stands y i e l d o n l y 4 7 $ as much per annum  as do the open s i t e s .  The g r e a t e s t r e d u c t i o n s o c c u r i n t h e  g r a s s and shrub components. F i g u r e 4 7 does not i n c l u d e t h e a n n u a l o f the t i m b e r a t each s i t e .  increment  The h i g h e s t a n n u a l t i m b e r  increment observed i n the study was  found a t t h e r a p i d l y  F i g u r e 46.  The a g g r e g a t e a n n u a l u n d e r s t o r y p r o d u c t i v i t y E s t e l l a Mountain as i n f l u e n c e d by c h a r a c t e r i s t i c s t a n d age. Only major components a r e i n c l u d e d .  of |  | Bearberry Soapolallie  Dwarf Shrubs jgjggl Forbs  ywA  Grass  200  H  150 gm/m  c  100  50  I  0  • I  25  T"  50  T  I  75  Characteristic  100  Stand  Age  1 125  1  150  Figure  47  The a g g r e g a t e a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a M o u n t a i n i n f l u e n c e d by f o r e s t canopy. O n l y m a j o r c o m p o n e n t s a r e shown.  Figure  47.  The a g g r e g a t e a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a Mountain as i n f l u e n c e d by f o r e s t canopy. Only major c o m p o n e n t s a r e shown.  ml  m mi  • •  200  as  Grasses Forbs Dwarf  Shrubs  Soapoiallie Bearberry  H  150  H  gm/m  £  100  50  J  1 J  0  10  T" 20  30  40  F o r e s t Canopy %  5 0  60  80  Table XVIII  The aggregate a n n u a l u n d e r s t o r y p r o d u c t i v i t y o f E s t e l l a  Mountain  SITE NAME Serai Fescue  Serai Bluebunch . Wheatgrass  Regen. D. F i r  Lodgepole  Larch  Grass  75  31  40  15  34  Forb  24  15  15  "ll  5  Dwarf shrub  3  11  6  12  2  Soapolallie  17.4  T  Bearberry  14  -  Total  Wt.  in  133.4  gm/m'  57  9.0 114  184.0  4.6  2.5  1.0  2  43.6  45.5  117 growing l o d g e p o l e p i n e s i t e (age 35 y e a r s ) .  The  older  s i t e s show a r e d u c t i o n i n p r o d u c t i o n , but remain h i g h e r t h a n the r a t e o f p r o d u c t i o n observed on Premier Ridge.  118  rv  DISCUSSION  The v e g e t a t i o n p a t t e r n s o f the t r e n c h f l o o r r e f l e c t the p r e v i o u s i n f l u e n c e s o f man.  The l o g g i n g o f t h e  e a r l y 1 9 0 0 ' s and t h e f i r e s o f t h e 1 9 3 0 ' s have l e f t a p a t c h work o f f o r e s t and open areas o f v a r y i n g s t a g e s o f t h e succession.  These areas a r e i n a s t a t e o f dynamic p r o -  g r e s s i o n ; most o f t h e a r e a i s p o t e n t i a l f o r e s t and i t i s t h i s d i r e c t i o n t h a t t h e p r o g r e s s i o n o r s u c c e s s i o n i s moving. C a t t l e and w i l d u n g u l a t e s p r e v i o u s l y r e s t r i c t e d i n t h e a r e a , a r e c u r r e n t l y e x p l o i t i n g these u n f o r e s t e d s e r a i  rangelands.  The p r e v i o u s e x i s t a n c e o f f o r e s t s on these l a n d s i s s t r o n g l y evidenced by the stumps which have remained i n t a c t ,  photo-  graphs and t h e r e c o r d s o f f i r e and l o g g i n g o f t h e a r e a . ': S i m i l a r records e x i s t f o r the east w a l l of the t r e n c h . The most n o t i c e a b l e e f f e c t o f t h e regrowth o f the f o r e s t on areas which f o r some twnty t o f o r t y y e a r s have remained w i t h o u t t r e e s , i s a r e d u c t i o n i n t h e p r o d u c t i v i t y o f t h e u n d e r s t o r y community upon w h i c h t h e g r a z e r s l a r g e l y depend.  The p a t t e r n o f r e g e n e r a t i o n has been one i n  which the more m o i s t a s p e c t s , such as t h e n o r t h e a s t and e a s t s l o p e s , stream channels and s m a l l draws have been first.  invaded  Thus t h e t r e e s tend t o c i r c u m s c r i b e areas then c l o s e  i n the r e m a i n i n g spaces.  T h i s i n v a s i o n has proceeded so  g r a d u a l l y t h a t i t f r e q u e n t l y goes u n n o t i c e d .  119  D i v e r s i t y i n c l i m a t e , v e g e t a t i o n and  soil  p r e v e n t e d the use of a system f o r randomly l o c a t i n g  sites  f o r i n t e n s i v e study.  The s i t e s were c a r e f u l l y s e l e c t e d  a f t e r g e n e r a l study.  D u p l i c a t i o n o f t h e e x c l o s u r e s was  not  p o s s i b l e due t o the c o s t r e q u i r e d f o r t h e i r c o n s t r u c t i o n . 1.  The Premier Ridge  Area  The removal o f t h e mature montane f o r e s t Premier Ridge between 1910 and  from  1 9 2 0 , and the subsequent  f o r e s t f i r e s l e d t o the e s t a b l i s h m e n t o f communities w i t h out t r e e s on v a r i o u s p a r t s o f the r i d g e w h i l e on o t h e r p a r t s r e g e n e r a t i o n o f f o r e s t commenced almost i m m e d i a t e l y .  The  f l o r i s t i c c o m p o s i t i o n o f the u n f o r e s t e d s e r a i communities has been a l t e r e d by g r a z i n g i n many r e g i o n s . r e l i c t Agropyron stock.  However, the  s i t e has r e c e i v e d l i t t l e g r a z i n g by  domestic  At p r e s e n t , 40 y e a r s a f t e r the l a s t major f i r e  s i x t y y e a r s a.fter l o g g i n g , t h i s s i t e had developed of bluebunch  and  a cover  wheatgrass ( 5 0 $ ) and j u n e g r a s s ( 9 $ ) .  Few  o t h e r g r a s s s p e c i e s and v e r y few f o r b s a r e p r e s e n t a t the site.  Under p r o l o n g e d p r o t e c t i o n from g r a z i n g and  without  the i n v a s i o n o f t r e e s , t h i s s i t e i s b e g i n n i n g t o t a k e on  the  c h a r a c t e r i s t i c s o f a. n a t u r a l g r a s s l a n d s i m i l a r i n n a t u r e t o the Skookumchuck P r a i r i e .  Since t h i s i s p o t e n t i a l l y  forest  l a n d , the A g r o p y r o n - K o e l e r i a community might be i n t h i s termed as d i s c l i m a x .  On the a d j a c e n t u n f o r e s t e d l a n d s  case  120 communities o f Poa spp. and S t i p a spp. a r e common.  The  i n i t i a t i o n o f f o r e s t growth on these s i t e s has a pronounced a f f e c t on t h e f l o r i s t i c s o f t h e g r a s s y s e r a . wheatgrass,  Bluebunch  Kentucky b l u e g r a s s and Canada b l u e g r a s s d i s a p p e a r  r a p i d l y ; rough f e s c u e and j u n e g r a s s may l i n g e r on i n t h e f o r e s t e d s i t e s b u t d i s a p p e a r as t h e canopy exceeds 6 0 $ . P i n e g r a s s , u s u a l l y o n l y an o c c a s i o n a l o r r a r e s p e c i e s i n the u n f o r e s t e d community, i n c r e a s e s r a p i d l y as t h e f o r e s t r e g e n e r a t e s , f o r m i n g t h e o n l y g r a s s p r e s e n t under v e r y dense f o r e s t c a n o p i e s .  To t h e c a s u a l o b s e r v e r , t h e r e l a t i v e  change i n abundance o f g r a s s s p e c i e s as t h e f o r e s t  develops  i n t h e f o r e s t e d s i t e s may go u n n o t i c e d . Forbs were v a r i a b l e i n abundance throughout t h e s u c c e s s i o n ; as w i t h g r a s s e s , h e l i o p h y t e s predominated  on  the u n f o r e s t e d a r e a s but g r a d u a l l y g i v e way t o t h e s c i o p h y t e s as t h e f o r e s t developed.  The more h e a v i l y g r a z e d . u n f o r e s t e d  s i t e s had many more s p e c i e s (22) than d i d t h e l i g h t l y g r a z e d open a r e a s  (5).  The shrubs were most abundant on t h e un-  f o r e s t e d a r e a s and e a r l y i n t h e f o r e s t s e r e s ; as f o r e s t canopy r e a d i n g s exceeded 5 0 $ shrub abundance d e c l i n e d . b r u s h was noted  t o be v e r y i n t o l e r a n t .  Bitter-  On t h e o t h e r hand,  s o a p o i a l l i e was more abundant I n t h e t i m b e r e d a r e a s , o f t e n e x i s t i n g under major b r e a k s i n t h e f o r e s t canopy.  Bear-  b e r r y was most common on t h e open communtles, b u t was common  121 In t h e v e r y young stages o f f o r e s t r e g e n e r a t i o n ; i t d e c l i n e d a g a i n under v e r y dense f o r e s t c a n o p i e s . The p r o d u c t i v i t y o f t h e communities o f t h e unf o r e s t e d areas was g e n e r a l l y depressed  by previous g r a z i n g .  P r o b a b l y few s i t e s were p r o d u c i n g n e a r optimum l 8 0 gm/m  2  (1,600  l b / a c . ) o f which t h e s e fenced s i t e s a r e c a p a b l e .  r e l i c t Agropyron community produced 6 5 gm/m  2  The  (579 lb/ac.)  o f g r a s s ; t h i s y i e l d appeared t o drop t o 3 4 gm/m  2  (307 lb/ac.)  as f o r e s t r e g e n e r a t i o n began and c o n t i n u e d t o d e c l i n e , r e a c h i n g a low o f 12 gm/m  2  (107 l b / a c ) .  Production i n the climax  f o r e s t appeared t o r i s e t o 25 gm/m , a l t h o u g h t h i s 2  quantifi-  c a t i o n o f t h e d e c l i n e i s approximate and a l t h o u g h i t may be m o d i f i e d b y changes i n f l o r i s t i c  composition.  The p r o d u c t i v i t y o f t h e f o r b s i s seemingly affected i n the general pattern o f the succession. n o t a b l e e x c e p t i o n was i n t h e c l i m a x ponderosa p i n e  little The o n l y stand  where f o r b p r o d u c t i o n was h i g h e s t ( 4 0 gm/m 356 l b / a c ) . 2  In  s p i t e o f t h e r e l a t i v e l y low y i e l d o f f o r b s when compared t o g r a s s e s , they a r e u n d o u b t e d l y used b y mule deer and w h i t e t a i l e d deer e a r l y i n t h e s p r i n g as t h e g r a s s i n i t i a t e s growth. The y i e l d b y b e a r b e r r y was h i g h e s t under open f o r e s t where canopies  range from 2 0 $ t o 4 0 $ ; on these s i t e s t h e y i e l d  was about 6 0 gm/m  2  (534 l b / a c ) .  Bitterbrush production  (annual t w i g s o f l e a f and  wood) was h i g h e s t i n t h e u n f o r e s t e d s i t e s and d e c l i n e r a p i d l y  122  as f o r e s t r e g e r n a t i o n began. yielded 6.3,  14.1  9 . 0 gm/m  2  (80 l b / a c ) .  2  sites  and 4 . 8 gm/m w i t h an average o f 8 . 4 gm/m  (75 l b / a c . ) o f b i t t e r b r u s h . was  The t h r e e u n f o r e s t e d  2  The p r o d u c t i o n i n c l i m a x P r o d u c t i o n on the o t h e r  s i t e s d i d not exceed 2 . 5 gm/m  2  (22 l b / a c . )  forest  forested  Bitterbrush i s  h e a v i l y used on the u n f o r e s t e d a r e a s o f the r i d g e and  protects  (from g r a z i n g ) many o f the g r a s s e s w h i c h d e v e l o p  under i t s  canopy.  grass  On the h e a v i l y g r a z e d  productivity  s i t e s most o f the  i s r e a l i z e d under the b i t t e r b r u s h p l a n t s where  i t i s not a v a i l a b l e t o g r a z e r s . • • , S o a p o i a l l i e p r o d u c t i o n on the t h r e e u n f o r e s t e d averaged 5 . 2 gm/m  2  (46 l b / a c . ) and reached i t s h i g h e s t  i n the e a r l y s t a g e s o f f o r e s t r e g e n e r a t i o n , 3 0 gm/m  2  sites  yield  (267  lb/ac).  As the s u c c e s s i o n proceeded beyond t h i s stage p r o d u c t i o n o f s o a p o i a l l i e d i d not exceed 2 . 5 gm/m  (22  2  The  f o r e s t stands  selected  lb/ac)  f o r s t u d y on Premier  Ridge i n c l u d e d Douglas f i r ( 3 ) * ponderosa p i n e ( 3 ) and lodgepole pine corresponding  ( l ) . The number o f stems per a c r e f o r each age o f t h e s u c c e s s i o n was h i g h e s t f o r lodge-  p o l e p i n e , f o l l o w e d b y Douglas f i r . lowest number o f s t e m s per a c r e .  Ponderosa p i n e had  The  a n n u a l Increment o f  wood p r o d u c t i o n f o r t h e f o r e s t s i t e s v a r i e d  from 5 0 . 5 f t ^ / year  i n the young Douglas f i r stand t o 5 - 7 f t , 3 / y e a r i n the forest.  the '  climax  The t i m b e r volume per a c r e ranged from 8 9 2 f t - 3 t o  123  to 1,729  f t ^ on the west s i d e o f the r i d g e .  The o n l y mature  Douglss f i r s i t e which c o u l d be found was on the n o r t h e a s t s i d e o f the r i d g e .  I t s t o t a l volume was  age o f 9 5 y e a r s the a n n u a l increment  f t 3 and a t an  3,593  o f t h i s s t a n d was  3 7 . 5 f t 3 / y e a r , r a t h e r h i g h when compared t o the west s i d e f o r e s t s o f s i m i l a r age.  W h i l e the south and w e s t e r n  aspects  a r e not s u i t e d t o the r a p i d p r o d u c t i o n o f t i m b e r , the n o r t h and  east s l o p e s grow t r e e s q u i c k l y .  T h i s f a c t may be u s e f u l  i n the f o r m u l a t i o n o f i n t e g r a t e d l a n d use p o l i c i e s f o r such areas. The n e t u n d e r s t o r y p r o d u c t i v i t y o f t h e u n f o r e s t e d s i t e s averaged 7 5 gm/m  2  to  l45  gm/m  2  (1,291  (839 l b / a c ) .  This value increased  l b / a c ) a s f o r e s t r e g e n e r a t i o n commenced.  In o l d e r stands the net u n d e r s t o r y p r o d u c t i v i t y t o l e s s than 40 gm/m  2  (356 l b / a c ) .  decreased  As these stands  reach  m a t u r i t y and n a t u r a l t h i n n i n g o c c u r s , a g r a d u a l i n c r e a s e i n net u n d e r s t o r y p r o d u c t i v i t y o c c u r s .  The c l i m a x stand o f  ponderosa p i n e exceeded the n e t p r o d u c t i v i t y o f any s i t e y i e l d e d 147 gm/m  2  (1,308  other  l b / a c ) . However i t i s  Important  t o r e c a l l t h a t the most v a l u a b l e component t o the g r a z i n g animal  (the g r a s s e s , f o r b s and b i t t e r b r u s h ) a l l decrease  markedly as r e g e n e r a t i o n o f the f o r e s t b e g i n s .  The  Increases i n y i e l d are l a r g e l y a t t r i b u t a b l e to bearberry s o a p o i a l l i e w h i c h exxjerience l i t t l e g r a z i n g .  and  Furthermore the  124  g r a s s o f t h e f o r e s t e d s i t e s i s p i n e g r a s s which has l i t t l e or  no n u t r i t i o n a l v a l u e as a w i n t e r f o r a g e and f r e q u e n t l y  i s n o t a v a i l a b l e beyond September o r l a t e August when i t s n u t r i t i o n a l v a l u e drops r a p i d l y and i s beaten down by f a l l r a i n s and snow storms. 2.  The E s t e l l a Mountain Area The E s t e l l a s i t e s have n o t been g r a z e d by domestic  stock.  The two major f a c t o r s g o v e r n i n g t h e i r p r e s e n t  sturcture  were t h e s e l e c t i v e l o g g i n g about 1 9 5 2 and t h e f i r e s o f 1 9 3 4 . The  e f f e c t o f e l e v a t i o n i s a prime i n h e r e n t h a b i t a t f a c t o r  for  the E s t e l l a  sites.  The f l o r i s t i c s o f t h e u n f o r e s t e d a r e a s o f E s t e l l a Mountain a r e n o t d i s s i m i l a r t o those o f t h e Premier area.  Ridge  Bluebunch wheatgrass o r rough f e s c u e u s u a l l y domin-  a t e t h e community; s e v e r a l o t h e r g r a s s e s were i n some e v i dence.  At t h e  5,900  was rough f e s c u e ; a t  f o o t e l e v a t i o n , t h e dominant bunchgrass 6,200  f e e t . i t was wheatgrass.  At t h i s  l a t t e r e l e v a t i o n the abundance o f the herbaceous c o v e r was d i s t i n c t l y l e s s than t h a t a t  5,900  feet.  P i n e g r a s s was  p r e s e n t in. the u n f o r e s t e d communities i n small, amounts (5$  c o v e r ) but I n c r e a s e d ( 3 5 $ c o v e r ) as f o r e s t r e g e n e r a t i o n  began. and  Rough f e s c u e and wheatgrass became markedly  e v e n t u a l l y d i s a p p e a r e d as t h e f o r e s t canopy  reduced  developed..  P i n e g r a s s i s t h e most e v i d e n t g r a s s s p e c i e s p r e s e n t i n dense s t a n d o f t r e e s .  125  Forbs w e r e g e n e r a l l y abundant a t a l l s i t e s on E s t e l l a and no t r e n d s i n abundance were d i s c e r n a b l e .  How-  e v e r , g i v e n t i m e , t h e b u n c h r a s s community below  feet  may  develop  6,000  as a d i s c l i m a x community s i m i l a r t o some on  Premier Ridge;  i n the s e r e s t o f o l l o w f o r b s may be reduced  i n the u n f o r e s t e d communities.  T h i s i s u n l i k e l y , however,  as t r e e r e g e n e r a t i o n may o c c u r on t h e s e s i t e s  before  s u f f i c i e n t time has passed t o e s t a b l i s h a " g r a s s l a n d " d i s c l i m a x community.  The shrubs  on E s t e l l a showed no major  trends w i t h regard t o the s u c c e s s i o n .  S o a p o i a l l i e was found  i n the dense stands o f l o d g e p o l e p i n e where i t e x i s t s p r i m a r i l y under gaps i n the o v e r s t o r y canopy. P r o d \ A c t l v i t y o f the g r a s s e s on the u n f o r e s t e d was  s i m i l a r t o t h a t on P r e m i e r Ridge.  y i e l d was 7 5 gm/m  5,900  f e e t the  ( 6 6 8 l b / a c . ) but had dropped t o 3 1 gm/m  2  (262  At  sites  2  lb/ac.) a t 6,200 feet.  The y i e l d o f g r a s s e s d e c l i n e d  r a p i d l y as f o r e s t r e g e n e r a t i o n o c c u r s .  Thirtyfive  years  a f t e r r e g e n e r a t i o n began, the p r o d u c t i v i t y o f the g r a s s component was  15 gm/m  2  (13^ l b / a c . ) .  This r a p i d d e c l i n e  i s due t o t h e v e r y r a p i d growth o f the t r e e s once they came e s t a b l i s h e d .  be-  At these e l e v a t i o n s p r e c i p i t a t i o n i s  a f f e c t i v e throughout  t h e summer and thus t h e growing p e r i o d  I s extended i n t o summer beyond t h a t found a t the v a l l e y bottom e l e v a t i o n s where growth I s c u r t a i l e d by mid Forb p r o d u c t i v i t y d e c l i n e s as t h e s u c c e s s i o n  July.  progresses,  126  b e i n g h i g h e s t on t h e u n f o r e s t e d s i t e s , 24 and 15 gm/m  2  a v e r a g i n g 15 gm/m  2  the h i g h f o r e s t  ( 1 3 5 l b / a c . ) and changed l i t t l e  canopy v a l u e s , 15 gm/m  2  under  (125 l b / a c ) .  Dwarf  shrubs a l s o d e c l i n e s t e a d i l y as t h e s u c c e s s i o n p r o c e e d s . B e a r b e r r y y i e l d s were h i g h e s t i n t h e m i d d l e f o r e s t range, sometimes as h i g h as Soapolallie  120  gm/m  produced v e r y l i t t l e  the u n f o r e s t e d a r e a s . canopy d e v e l o p e d .  2  (1,068  ( 1 7 gm/m  2  canopy  lb.ac).  ( 1 5 1 l b / a c . ) on  The y i e l d I n c r e a s e d as t h e f o r e s t  Representative y i e l d s f o r the timbered  a r e a s were about 4 5 gm/m  2  (401 l b / a c ) .  The t i m b e r p r o d u c t i o n on E s t e l l a was, as might be expected from p r e c i p i t a t i o n  e f f e c t i v e n e s s d a t a , much  b e t t e r than t h e p r o d u c t i o n reached on P r e m i e r R i d g e .  The  two s e l e c t i v e l y logged s i t e s had a,n a n n u a l increment o f 38 f t 3 and 27 f t , 3 .  The young l o d g e p o l e s i t e has an annua1  growth r a t e o f 6 8 f t 3 o f t i m b e r p e r y e a r p e r a c r e . The d i f f e r e n c e between P r e m i e r Ridge and E s t e l l a Mountain ca.n l a r g e l y be a t t r i b u t e d  t o the increased  of the l a t t e r and t h e consequences  of effect o f microclimate.  The i n c r e a s e d summer r a i n f a l l , extends t h e growing  elevation  season  a.nd a l t h o u g h t h e t e m p e r a t u r e s a r e l o w e r , t h e a v a i l a b l e and e f f e c t i v e m o i s t u r e i s much g r e a t e r than i t i s f o r Premier Ridge. The n e t pr o d u c t i v i t y o f t h e u n d e r s t o r y on E s t e l l a  127  g e n e r a l l y d e c l i n e s as t h e s u c c e s s i o n p r o g r e s s e s .  An i n -  c r e a s e i n y i e l d i s n o t e d i n t h e youngest stage o f t h e r e generation cycle studied.  T h i s i n c r e a s e was e n t i r e l y due  to a h i g h y i e l d h y b e a r b e r r y .  Those components which may b  considered u s e f u l to n a t i v e ungulates, the grasses, forbs and dwarf s h r u b s , g e n e r a l l y d e c l i n e i n y i e l d as t h e f o r e s t r e g e n e r a t i o n proceeds.  W h i l e g r a s s p r o d u c t i o n may be  moderate under some f o r e s t s t a n d s , t h e s p e c i e s c o m p o s i t i o n (mainly pinegrass) i s not s u i t e d to w i n t e r i n g ungulates. Trad i t lona], l y , s t u d i e s which have compared t h e e f f e c t o f t h e f o r e s t on u n d e r s t o r y p r o d u c t i v i t y , have e l i m i n a t e d t h e s u c c e s s i o n a l element i n an attempt t o remove as many v a r i a b l e s as p o s s i b l e .  Pase  (1958)  com-  pared t h e herbage p r o d u c t i o n and s p e c i e s c o m p o s i t i o n under immature ponderosa p i n e i n t h e B l a c k H i l l s .  Stand age was  h e l d c o n s t a n t , b u t a r t i f i c i a l t h i n n i n g had produced  stands  v a r y i n g i n f o r e s t canopy from 0 $ t o 7 1 $ and w i t h a base a r e a from 0 t o 215 f t p e r a c r e . 2  Pase ( i b i d ) found t h a t  g r a s s p r o d u c t i o n on open ( u n f o r e s t e d ) a r e a s was 7 4 times g r e a t e r than wa.s produced  i n stands which had a b a s a l  a r e a o f 215 f t p e r a c r e .  Forbs and shrubs were a l s o  2  i n t o l e r a n t t o i n c r e a s e d f o r e s t canopy, p r o d u c i n g l e s s  than  50 l b / a c . o f a i r - d r i e d f o r a g e under a canopy o f 7 1 $ .  Halls  and S c h u s t e r ( 1 9 ^ 5 ) s t u d i e d herbage p r o d u c t i o n i n p i n e -  128  hardwood f o r e s t s i n Texas, measured herbage, f o r e s t  cover  p e r c e n t and t r e e b a s a l a r e a b u t made no mention o f t h e age o f t h e stands o r t h e i r s u c c e s s i o n a l s t a t u s . . D e s p i t e a c o n s i d e r a b l e volume o f l i t e r a t u r e , t h e concept  o f a b a l a n c e between t h e f o r e s t and i t s u n d e r s t o r y  has n o t been c l o s e l y examined.  Individual  investigation  ( u s u a l l y proponents o f one t h e o r y ) have r e p o r t e d t h e r e s u l t s o f experiments  d e s i g n e d t o show t h a t e i t h e r  light  or r a i n f a l l l i m i t understory p r o d u c t i v i t y conversely, Barrett  (1965).  B a r r e t t and Youngberg  (1965)  have shown  t h a t a heavy u n d e r s t o r y i n h i b i t s o r m i n i m i z e s wood p r o duction.  McConnell  and Smith  (1970) reported that thinning  dense (2,800 stem/ac.) stands o f ponderosa p i n e r e s u l t e d i n dramatic  increases i n understory p r o d u c t i v i t y eight years  f o l l o w i n g the t h i n n i n g .  These r e s u l t s suggest  that there  may be a c t i v e c o m p e t i t i o n f o r some m a t e r i a l , p o s s i b l y water o r n u t r i e n t s , between t h e f o r e s t and t h e u n d e r s t o r y . In a d d i t i o n t o t h e annual y i e l d o f a. p i e c e o f l a n d t h e r e i.s a l s o a. "maintenance c o s t " which must be c o n s i d e r e d .  This  c o u l d be r e c o g n i z e d as t h e energy r e q u i r e d t o m a i n t a i n t h e p l a n t biomass a l i v e d u r i n g t h e y e a r . On t h e u n f o r e s t e d a r e a s t h e t o t a l p r o d u c t i v i t y i s c h a n n e l l e d i n t o t h e p r o d u c t i o n o f g r a s s e s , f o r b s and shrubs; t h e l a r g e s t p a r t o f which i s . a v a i l a b l e t o g r a z e r s .  129  As f o r e s t r e g e n e r a t i o n commences and t h e t i m b e r matures, more and more o f the n u t r i e n t s a r e taken up by the f o r e s t t o form the new  growth and t o m a i n t a i n the e x i s t i n g volume  of l i v i n g t i s s u e .  Hence t h e r e a r e l e s s n u t r i e n t s  freely  a v a i l a b l e t o the u n d e r s t o r y community.' Grasses and f o r b s  :  do not expend much energy m a i n t a i n i n g the p r e v i o u s y e a r ' s growth above the ground s u r f a c e .  Shrubs,•• h o w e v e r d o r e -  q u i r e some energy t o m a i n t a i n t h e t i s s u e s developed previous years.  in  The volume o f t h i s t i s s u e , on a u n i t a r e a  b a s i s , i s much l e s s than f o r t r e e s . As v e g e t a t i o n p r o g r e s s e s from open r a n g e l a n d t o timbered range, each s u c c e e d i n g y e a r sees more and more energy and n u t r i e n t s t i e d up i n t h e maintenance and o f the t r e e s .  growth  I r r e s p e c t i v e o f the e f f e c t s o f the f o r e s t  canopy on the u n d e r s t o r y i t i s not s u r p r i s i n g t h a t unders t o r y p r o d u c t i v i t y decreases as the biomass o f the t r e e s increases. There i s no q u e s t i o n t h a t as a s u c c e s s i o n p r o g r e s s e s from u n f o r e s t e d t o f o r e s t e d l a n d , a d r a m a t i c c r e a s e i n the xanderstory t a k e s p l a c e . d e c l i n e i s most apparent  Furthermore,  dethis  i n t h a t p a r t o f t h e community which  i s g e n e r a l l y r e c o g n i z e d t o be o f most b e n e f i t t o g r a z i n g animals.  A l l but a few o f the c r i t i c a l w i l d l i f e w i n t e r  ranges which o c c u r on the f l o o r of the s o u t h e r n Rocky  130  Mountain Trench a r e p o t e n t i a l l y f o r e s t .  Tree r e g e n e r a t i o n  has begun on a l l o f t h e s e a r e a s and i s w e l l underway on Premier Ridge.  As t h e open u n f o r e s t e d range acreage s h r i n k s  a n n u a l l y , t h e g r a z i n g p r e s s u r e on t h e r e m a i n i n g open a r e a s becomes more i n t e n s e .  Many communities,  particularly  those  n e a r water and on l e s s steep t e r r a i n a r e a l r e a d y o v e r grazed.  There i s a v a l u e t o t h e t i m b e r which w i l l  develop  on many a r e a s , p a r t i c u l a r l y t h e n o r t h and n o r t h e a s t s l o p e s . The p e r i o d between c u t s on t h e south and s o u t h w e s t e r n i s about 200 y e a r s .  aspects  The economic v a l u e o f such a h a r v e s t i s  p r o b a b l y v e r y s m a l l when c o n s i d e r e d on an a n n u a l b a s i s .  If  f o r e s t r e g e n e r a t e s on t h e c r i t i c a l s l o p e s , t h e o p t i o n o f w i l d l i f e t o use t h e v a s t a l p i n e summer ranges of  i n the heart  t h e Rocky Mountains ( l a r g e l y untouched by man a t p r e s e n t )  w i l l be l o s t .  T h i s would g r e a t l y decrease t h e " u s e f u l "  p r o d u c t i v i t y o f these a l p i n e a r e a s from t h e s t a n d p o i n t o f human b e n e f i t , t o b o t h consumptive and non-consumptive u s e r s of  the resource.  In a d d i t i o n , I f regeneration continues,  s u b s t a n t i a l summer ranges  f o r c a t t l e w i l l be l o s t and m a r g i n a l  ranches o f the a r e a w i l l be u n a b l e t o r e p l a c e t h e s e g r a z i n g a r e a s i n a v a l l e y where i n d u s t r y and human p o p u l a t i o n a r e increasing  rapidly.  131  REFERENCES CITED A n d e r s o n , R. C , 0 . L. L o u c k s and A. M. S w a i n . 1 9 6 9 . Herba c e o u s r e s p o n s e t o c a n o p y c o v e r , l i g h t i n t e n s i t y , and t h r o u g h f a l l p r e c i p i t a t i o n In c o n i f e r o u s f o r e s t s . Ecology. 5 0 ( 2 ) : 2 5 5 - 2 6 3 . A r n o l d , J . F. 1 9 5 0 . Changes i n p o n d e r o s a p i n e b u n c h g r a s s r a n g e s i n N. A r i z o n a r e s u l t i n g f r o m p i n e r e g e n e r a t i o n and g r a z i n g . J . F o r e s t r y 48:118-126. B a r r e t t , J . W. 1965. S p a c i n g and u n d e r s t o r y v e g e t a t i o n a f f e c t growth o f ponderosa p i n e s a p l i n g s . Pacific F o r e s t and Range Exp. S t a . U. S. Rep. A g r . , F o r e s t S e r v . Res. N o t e PNW 2 7 , 8 p.  N.W.  Center f o r N a t u r a l Resources (ed). 1969. Coniferous F o r e s t s o f t h e N o r t h e r n R o c k y M o u n t a i n s . U n i v e r s i t y o f Montana F o u n d a t i o n , M i s s o u l a . 3 9 5 PP • D a u b e n m i r e , R. F. 1 9 4 3 . Vegetational zonation Mountains. B o t . Rev., 9:325-393. _____ ern  i n the  Rocky  1946. The l i f e - z o n e p r o b l e m i n t h e n o r t h intermountain region. Northwest S c i . 2 0 : 2 8 - 3 8 .  . 1959. A c a n o p y c o v e r a g e method o f vegetational analysis. Northwest S c i . 3 3 * 4 3 - 6 4 . D e m a r c h i , D. A. 1 9 6 8 . Ecology o f the Premier Ridge b i g h o r n w i n t e r range. Mimeo R e p o r t t o B. C. F i s h and W i l d l i f e B r a n c h . 35 P• Dodd, C. 1969. The r e l a t i o n s h i p o f h e r b a c e o u s u n d e r s t o r y growth to t r e e o v e r s t o r y . 75 pp. B.Sc. T h e s i s , U n i v . o f B. C. D e p t . o f P l a n t S c i e n c e . E h r e n r e i c h , J . H. and J . S. C r o s b y , d u c t i o n i s r e l a t e d t o hardwood  i960. Herbage procrown c o v e r . J . F o r e s t r y  58:564-565.  G a i n e s , E. M., R. S. C a m p b e l l and J . J . B r a s i n g t o n . 1 9 5 4 . F o r e s t p r o d u c t i o n on l o n g l e a f p i n e l a n d s o f s o u t h e r n Alabama. Ecol. 35:59-62. G a r r i s o n , G. H. i 9 6 0 . Recovery of ponderosa p i n e range i n e a s t e r n Oregon and e a s t e r n W a s h i n g t o n b y t h e 7 t h y e a r after logging. P r o c . Soc. Amer. F o r . i 9 6 0 , I96I: pp.  137-139.  132  H a l l s , L. K. and J . L. S c h u s t e r . 1 9 6 5 . Tree-herbage r e l a t i o n s i n t h e pine-hardwood f o r e s t s o f Texas. J. Forestry 63(2) :282-283. Jameson, D. A. 1 9 6 7 . The r e l a t i o n s h i p o f t r e e o v e r s t o r y and and herbaceous u n d e r s t o r y v e g e t a t i o n . J . Range Man. 20(4):247-250.  K e l l y , C. C. and P. N. S p r o u t . 1 9 5 6 . S o i l s u r v e y o f t h e upper Kootenay and E l k R i v e r v a l l e y s . Report No. 5 B r i t i s h Columbia S o i l Survey. 9 9 p. M c C o n n e l l , B. R. and J . G. Smith. 1 9 7 0 . Response o f unders t o r y v e g e t a t i o n t o ponderosa p i n e t h i n n i n g i n e a s t e r n Washington. J . Range Man. 2 3 ( 3 ) : 2 0 8 - 2 1 2 . Ormerod, D. W. 1 9 6 8 . Improved i n s t r u m e n t a t i o n f o r e s t i mating t h r e e crown h o r i z o n t a l dimensions by v e r t i c a l p r o j e c t i o n . Unpubl. B.S.F. T h e s i s . U n i v . o f B r i t i s h Columbia. 44 p. Pa.se. C. P. and R. M. Hurd. 1 9 5 8 . U n d e r s t o r y v e g e t a t i o n as rela.ted t o b a s a l a r e a , crown c o v e r and l i t t e r produced by immature ponderosa p i n e s t a n d s i n t h e B l a c k H i l l s . Soc. Amer. F o r e s t e r s P r o c . 1 9 5 7 : 1 5 6 - 1 5 8 . Q u a e d v l i e g . M. T. 1 9 6 9 . P r o d u c t i v i t y , age and g e n e r a l e c o l o g y o f b i t t e r b r u s h on t h e B u l l R i v e r and P r e m i e r Ridge r a n g e s . B. Sc.A. T h e s i s , Dept. o f P l a n t S c i . Univ. o f B r i t i s h Columbia. Runka, G. B. 1 9 7 0 . Lands o f t h e E a s t Kootenay. Report t o the B.C. S o i l C a p a b i l i t y f o r A g r i c u l t u r e and F o r e s t r y Committee. Mimeo. 1 8 0 p. Smith, J . H. G. and R. E. Breadon, 1 9 6 4 . Combined v a r i a b l e e q u a t i o n s and v o l u m e - b a s a l a r e a r a t i o s f o r t o t a l c u b i c f o o t volumes o f t h e commercial t r e e s o f B. C. F o r . Chron. 40(2)  :258-26l.  Stokes,, M. A. and T. L. S m i l e y . 1 9 6 8 . An i n t r o d u c t i o n t o t r e e r i n g d a t i n g . C h i c a g o , U n i v . o f Chicago P r e s s 1-73-  W e s t l a k e . D. G. 1 9 6 3 . Comparisons o f p l a n t p r o d u c t i v i t y . B i o l . Rev. 3 8 ( 2 ) . - 3 8 5 - 4 2 5 .  133  Young; J . A., J . A. B. McArthur and D. W. H e d r i c k . 1 9 6 7 . Forage u t i l i z a t i o n i n a m i x e d - c o n i f e r o u s f o r e s t o f n o r t h e a s t e r n Oregon. J . F o r e s t r y 3 5 : 3 9 1 - 3 9 3 . •  134  APPENDIX I The p h y s i c a l c h a r a c t e r i s t i c s o f t h e s i t e s on P r e m i e r Ridge and E s t e l l a M o u n t a i n . Premier Ridge S i t e Name  Aspect  % Slope  E l e v a t i o n I n Feet  Skookumchuck P r a i r i e  Nil  0  2,610  R e l i c t Bunchgrass  260°  43  3,475  260°  31  3,150  Poa - S t i p a  270°  30  2,920  Young Douglas F i r  270°  ll  3,090  Middle-aged Douglas F i r 250°  18  3,050  45  3,200  3  3,010  13  2,920  28  2,885  4  2,970  Bitterbrush  '  Mature Douglas F i r Young Ponderosa P i n e  5.0°' 0  M i d d l e - a g e d Ponderosa Pine  210°  C l i m a x Ponderosa P i n e  260°  Lodgepole P i n e  0  E s t e l l a Mountain S e r a i Bunchgrass  240°  6o  6,200  S e r a i Fescue  260°  47  5,950  R e g e n e r a t i n g Douglas F i r 290°  5  4,170  Larch  280°  33  4,220  Lodgepole P i n e  260°  45  5,980  APPENDIX  Key  to the s i t e s  on  1  Mature Douglas f i r  2  Young D o u g l a s f i r  3  Middle-aged Douglas f i r  4  Young p o n d e r o s a  5  Middle-aged pondrosa  6  Lodgepole  7  Poa-Stipa (unforested)  8  Bitterbrush  9  Bluebunch wheatgrass  II  P r e m i e r R i d g e , map  pine pine  pine  (Purshia) unforested unforested  on n e x t  page.  135  APPENDIX I I I • . L i s t o f p l a n t s found on t h e study- a r e a s ; common and s c i e n t i f i c names l i s t e d . S c i e n t i f i c Name  Common Name  Grasses Agropyron  s p l c a t u m v a r . inerme  B e a r d l e s s wheatgrass o r bluebunch wheatgrass•  Bromus t e c t o r u m  Downy brome, downy chess  Festuca  Rough f e s c u e  scalrella  Koeleria  cristata  Junegrass  Poa compressa  Canada b l u e g r a s s  Poa p r a t e n s i s  Kentucky b l u e g r a s s  Stipa  Columbia  columhiana  needlegrass  Stipa rlchardsoni  Richardson needlegrass  Stipa williamsonli  Williams needlegrass  Forbs Achilles millefolium  Yarrow  A l l i u m cernnum  Nodding o n i o n  Anaphalls margarltocea Anemone mult.if i d a  Globe anemone  Anemone patens  Pas que f l o w e r •  A n t e n n a r i a racemosa A r a b i s drummondii  Drummond's r o c k e r e s s  Arnica  Heart-leaf arnica  cordifolia  Aster consplcuus '  Large p u r p l e a s t e r o r showy aster  Astragalus miser  Timber m i l k v e t c h  137  Balsamorhiza Calochortus  sagittata elegans  Spring  sunflower  Elegant mariposa  lily  Calochortus macrocarpus  Green banded mariposa  Calypso  F a l s e lady  bulbosa  Componula r o t u n d i f o l l a  Bluebell  Carex  Various  spp.  Castille.ja minlata Crepls  slipper  sedges  Indian p a i n t b r u s h  atrabarba  Ep 1 lob ium minatum E r i g e r o n compos!tus Erigeron  Fleaban e  fillfollus  E r i g e r o n speceosus Eriogonum umbellaturn  Sulphur  eriogonum  Galliardia arstita  Blanket  flower  Gent1ana a m a r e l l a Geum t r i f l o r u m Hedysarum  sulphurescens  Hieraclum  albiflorum  Hierocium  umbellaturn  White hawkweed  Lesquerella Douglasii Lewisia red!viva  B i t t e r root  Linum l e w i s s i  Wild  Lithospermum r u d e r a l e  Puccoon  Lomatium macrocarpum  flax  138  Lomatium  triternatum  Oxytropxas  compestrls  Narrow-leaved Locoweed  Penstemon p r o c e r u s  Little  Phacelia  Mountain  Phlox  servicca  caespitosa  parsley  flower  Tufted  penstemon  phacelia  phlox  PolemonIum p u l c h e r r i m u m Pyrola. secunda Sedum s p p . Senecio  Stonecrop  canus  Sisyrlnchium spp. Saildago  Blue eyed  grass  multirudiata  Stenonthlum  Occidentale  Bronze  bells  Trapapogon dublus  Oyster  plant  V i o l a , a dune a  Blue  Zygadenus  Mountain death  elegans  Zygadenus yenenosus  violet camas  D e a t h camas  Dwarf Shrubs Amelanchier Berberis  alnifolia.  nervosa  Saskatoon b e r r y  Mahonia o r Oregon g r a p e  Linnaea b o r e a l i s  Twin  R o s a gymnoca.rpu  Dwarf r o s e  Spiraea  Flat-top  lucidea.  (serviceberry)  flower  spiraea  139  Other Shrubs Arctostaphylos Uva-ursl  Kinnikinnik  C l e m a t i s Columbiana  Blue clematis  Phlladelphus  Mock orange  Purshia  lewisli  tridentata  Shepherdia  canadensis  Symphorlcarpus a l b a  or bearberry  Bitterbrush Soapoiallie, Snowberry  bearberry

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UBC Theses and Dissertations

UBC Theses and Dissertations

Secondary autogenic succession in the southern Rocky Mountain Trench Kemper, John Bryan 1971

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Open Collections

UBC Theses and Dissertations

Secondary autogenic succession in the southern Rocky Mountain Trench Kemper, John Bryan 1971

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